Renewable energy integration into the power grid has prioritized large-scale energy storage. Electrochemical energy conversion and storage systems increasingly employ anion-exchange membranes, notably alkaline anion forms, and redox flow batteries for medium to large-scale power storage. AEMs may exchange anions and covalently bound cations such as quaternary ammonium. However, redox flow batteries are too expensive for widespread use. Redox flow batteries' performance and profitability depend on the membrane. Despite electricity traveling across the membrane dividing positive and negative electrolytes, ions complete the circuit. Ideally, membranes have strong ionic conductivity, low water input, and chemical and thermal stability. Also crucial is ionic exchange. Many groups worldwide have spent years building an inexpensive, chemically stable redox flow cell battery membrane. Eco-friendly zinc-iron redox flow batteries employ an anion exchange membrane that fulfills these requirements.

Excerpt

ABSTRACT

1. INTRODUCTION
1.1. SOURCES OF ENERGY
1.1.1. Renewable Sources
1.1.2. Other Energy Sources
1.2. BATTERY
1.2.1. Principle of Operation
1.2.2. Types of Batteries
1.3. ELECTROCHEMICAL CELL OR A GALVANIC CELL
1.4. HISTORY OF ION EXCHANGE MATERIALS
1.4.1. Ion Exchange Material
1.4.2. Types of Ion Exchange Materials
1.4.3. Mechanism of Ion Exchange Process
1.4.4. Kinetics of Ion Exchange Materials
1.4.5. Ion Exchange Capacity (IEC)
1.4.6. Ion Exchange Membrane
1.4.7. Types of Ion Exchange Membranes
1.4.8. Preparation of Membranes
1.4.8. Advancements in AEM Preparation Methods
1.4.9. Desired Properties of AEM
1.4.10. Transport Mechanisms in AEM
1.4.11. Chemical Stability of AEM
1.4.12. Mechanism of Degradation of Cationic Group
1.4.13. Effect of Crosslinking
1.4.14. AEM Fabrication Methods
1.4.15. Applications of AEMs
1.4.16. Fuel Cells
1.4.17. Fuel cell classifications

2. LITERATURE REVIEW.

3. MATERIALS & METHODS
3.1. MATERIALS USED
3.2. EXPERIMENTATION

4. RESULT AND DISCUSSION

5. CONCLUSIONS

REFERENCES

ABSTRACT

Renewable energy integration into the power grid has prioritized large-scale energy storage. Electrochemical energy conversion and storage systems increasingly employ anion-exchange membranes, notably alkaline anion forms, and redox flow batteries for medium to large-scale power storage. AEMs may exchange anions and covalently bound cations such as quaternary ammonium. However, redox flow batteries are too expensive for widespread use. Redox flow batteries’ performance and profitability depend on the membrane. Despite electricity traveling across the membrane dividing positive and negative electrolytes, ions complete the circuit. Ideally, membranes have strong ionic conductivity, low water input, chemical, and thermal stability. Also crucial is ionic exchange. Many groups worldwide have spent years building an inexpensive, chemically stable redox flow cell battery membrane. Eco-friendly zinc-iron redox flow batteries employ an anion exchange membrane that fulfills requirements.

1. INTRODUCTION

Global electricity demand is rising quickly. The globe is reportedly experiencing its worst energy crisis. Economic growth and better domestic power distribution have driven electricity demand up considerably despite decreasing energy usage over the previous 20 years [1]. The United Nations Environment Programme (UNEP) and World Meteorological Organization (WMO) formed the Intergovernmental Panel on Energy (IGEL) in 1988 because energy is linked to global challenges including poverty, climate change, environmental difficulties, and food security [2].

Thousands of famous scientists and other professionals volunteer to examine climate change research to solve environmental and energy problems. The Panel and former US Vice President Albert Arnold Gore, Jr. won the 2007 Nobel Peace Prize for this effort. Switching to renewable and low-carbon energy is important for society’s sustainability. World population growth uses more energy. The International Energy Agency (IEA) predicts half the global energy use in 2030. Over 150 affluent nations signed the Kyoto Protocol in 1997 in Kyoto, Japan, to reduce greenhouse gas emissions. Carbon capture and storage protocols and the Intergovernmental Panel on Climate Change (IPCC) report stress reducing atmospheric CO₂ emissions [3-7].

Biofuels, photovoltaics, wind, geothermal, tidal, hydroelectric, etc. are renewable energy sources. Renewable power must be affordable and dependable to compete with fossil fuels. There are few effective energy storage options, making it hard to integrate them into the electrical system. Modern society needs efficient, environmentally friendly, and economically feasible energy conversion and storage solutions to address growing ecological concerns. Because fossil fuels cause climate change and environmental damage, numerous nations have reformed their power-generating systems. Renewable energy sources are intermittent and non-dispatchable; therefore, energy storage prevents supply-demand blackouts. This makes supply-demand matching questionable. Redox flow batteries and fuel cells can address these needs. Various sectors may use ion exchange membranes to alleviate energy shortages and pollution. Ion exchange membranes are utilized in polymer electrolyte fuel cells, redox flow batteries, water and gas purification, and more. Ion exchange membranes keep positive and negative ions apart and complete the circuit when electricity passes through them.

1.1. SOURCES OF ENERGY

Energy can be renewable or nonrenewable

1.1.1. Renewable Sources

Nature renews sun, wind, ocean, hydropower, biomass, geothermal, biofuel, and hydrogen. Renewable power must be affordable and dependable to compete with fossil fuels. There are few effective energy storage options, making it hard to integrate them into the electrical system. Modern society needs efficient, environmentally friendly, and economically feasible energy conversion and storage solutions to address growing ecological concerns.

1.1.2. Other Energy Sources

Non-renewable energy cannot be sustained for us or future generations. Coal, petroleum, and natural gas provide the most nonrenewable energy. The primary component of fossil fuels is carbon. Carboniferous fossil fuels were formed 360–300 million years ago. Problem: they release greenhouse gases like CO₂. Additional environmental impact comes from its byproducts. Pricey and hard to replenish when they run out. To preserve energy for future use we need to have a suitable storage system. Among all of them, battery storage is preferable.

1.2. BATTERY

Scientists and technicians convert chemical energy to electricity using batteries. Battery components include anode (-), cathode (+), and electrolyte. Conductive electrolyte serializes voltaic cell halves. An electrical circuit links a battery’s cathode and anode, the positive and negative ends. Electron accumulation at the anode increases battery size and bulk owing to chemical processes. Single-unit cells are small and light. Each voltaic cell, two half cells linked in series by the conductive electrolyte, delivers electricity for less time.

1.2.1. Principle of Operation

Batteries directly generate electricity from chemicals. Electrochemical processes use metal, oxide, or molecular cohesive or bond energies to generate electricity. Unlike transition metals, d-electron bonding does not stabilize high-energy metals like zinc and lithium. Assume energy storage. A battery’s energetically beneficial redox reaction requires electrons to move outside the circuit. Battery cells are voltaic. Each cell has two half-cells linked by a metal cation electrolyte. Anions go to the cell’s negative electrode and cations to its positive electrode. Both cell halves have electrolytes. The cathode decreases cations and the anode oxidizes metals. A divider separates half-cell electrolytes and allows ion passage to complete the electrical circuit. Half-cells have volts of electric potential compared to benchmarks. Cells’ net electromotive forces (EMFs) are half-cells’ EMFs eliminated. Half-reaction reduction potential creates the net electromotive force. Terminal voltage (difference) measures cell terminal electrical force in volts. In an uncharged cell, the terminal open-circuit voltage = emf. Internal resistance lowers a cell’s terminal voltage while discharging and raises it when charging.

1.2.2. Types of Batteries

There are two types: Primary and secondary batteries

(a) Primary Battery

After discharge, delivering current in the opposite direction cannot recharge a primary cell or battery since the process is sometimes irreversible. Once-used dry cell primary batteries are replaced. Dry-cell zinc-carbon batteries. Electrode and container zinc cans. Carbon rods in ammonium chloride, carbon powder, manganese (IV) oxide, zinc chloride, and a trace of water form a positive electrode. Standard zinc oxidation best represents anode reaction:

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Multiple cathode reactions complicate it. An about-length chain reaction happens at the cathode

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Draining the battery reduces potential from 1.5 V. Remember that battery size affects voltage.

The voltage of D, C, A, AA, and AAA batteries is the same. More electron moles come from larger batteries.

(a) Secondary Battery

A circuit may reverse current flow to recharge a cell or battery before discharging it. Charge and discharge cycles can range from a few to a hundred, depending on technology. Smartphones, tablets, and cars use rechargeable secondary batteries.

1.3. ELECTROCHEMICAL CELL OR A GALVANIC CELL

Electrochemical and galvanic cells generate electricity from chemicals. Galvanic and voltaic cells are electrochemical cells named after Luigi Galvani and Alessandro Volta. A salt bridge or porous membrane connects two metals in an electrolyte or half-cell with distinct metals and their ions in solution. Inside these cells, indirect reactions occur [8-13].

A salt bridge

In a lab, a salt bridge links voltaic cell oxidation with reduction. Electrically neutralize the cell’s internal circuit to slow equilibrium. Without a salt bridge, the cell’s halves’ solutions would soon collect opposing charges, stopping power generation. A salt bridge battery has various drawbacks. This includes liquid junction potential, electrolyte mixing, a high possibility of a direct reaction that would destroy the battery, and the inability to create the expected EMF.

1.4. HISTORY OF ION EXCHANGE MATERIALS

We’ve long practiced “ion exchange”-replacing one ion in a solution with another in water. Renaissance Mediterranean ceramics used thin glass films with silver and copper nanoparticles on ceramic substrates. A combination of copper and silver salts and oxides, vinegar, ochre, and clay deposited copper/silver on glazed pottery. Smoke agents in the 6,000 oC kiln lowered the system. Glass transferred metal and alkali ions in these circumstances. English agricultural specialists Thompson and Way found that some soils absorbed ammonia from fertilizers better than others, even though cation exchange was just created a century earlier. Complex soil silicates transferred ions. These composites were created in the lab with sodium silicate and aluminate. Rober Gans used these substances to cure sugar and soften water in 1906. Adams and Holmes invented organic ion exchangers in 1935 using crushed phonograph records [14-17].

1.4.1. Ion Exchange Material

Ion exchange chemically exchanges similar-charged ions in a solution for free-moving ions of a solid, the ion exchanger. The exchanger needs an open inorganic or organic network to move ions. Insoluble in water, ion exchangers can exchange ions for similarly charged ones in liquids. This description includes everything. Using “substance” instead of “compound” includes many interchangeable components, including naturally occurring substances with unknown chemical composition. Thus, “medium” for ion exchange includes aqueous and non-aqueous solutions, molten salts, and vapor contact [8,9]. Ion exchange may remove ions from aqueous solutions in several insoluble chemical solvents. It also indicates an ion exchange. Simply, the exchanger touches the transaction medium. A water-based solution and solid ion exchanger are usual. The exchanger must be ionized to exchange ions. An exchanger may exchange one ion since all ions are insoluble. Picture the ion exchanger as M+X−, ionized (M+ being the soluble ion), submerged in salt NY, resulting in N+ and Y−:

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These salts MX and NY react like displacement reactions. The equation may be simplified by removing the Y− ion from both sides, as it is not involved in the reaction.

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If the exchanger’s insoluble ion is a cation, this equation works. Some polymers chelate depending on their chemical environment; hence ion exchange resin and chelating resin are interchangeable. Both ion exchange and sorption entail a solid absorbing a dissolved component at a surface. These events differ because ion exchange is stoichiometric. The solution acquires charging ions for every ion to be eliminated. Without replacement, sorption is nonstoichiometric solute intake.

Many materials fulfill the two ion exchange requirements—a supporting material with fixed ionic charges and a solution-permeable substance—unexpectedly. Fixed expenses can be positive or negative. To work, mobile and stationary ions must be oppositely charged. Cation exchange involves fixed negative charges exchanging positive cations. Ion exchanges include positive and negative charges.

1.4.2. Types of Ion Exchange Materials

Natural and synthetic ion exchange materials exist.

(a) Natural Organic Products

Some organic compounds can swap ions chemically. Due to carboxyl groups in amphoteric proteins, plants and animals may exchange ions. These carboxyl and phenolic groups (-CO₂H and -OH) exchange hydrogen ions for other cations under neutral or slightly acidic circumstances. Exchangers include soil “humus” humin and acids and partly degraded and oxidized plant debris acid groups. These organic goods include paper filter sheets for ion exchange separations and processed cellulose fibers for columns. Oxidizing wood, fibers, peat, and coal with nitric acid or strong sulfuric acid adds the very acidic sulphonic acid group (-SO₃H) to make ion exchangers.

(b) Natural Inorganic Products

Many natural mineral complexes exchange ions. Vermiculite, bentonite, kaolinite, illite, and zeolites. The first ion exchange materials were natural zeolites. Ion exchange, restricted permeability, and workability make clay materials good for radioactive waste backfill and buffers. Clays can be utilized in batch ion exchange but not columns since they block bed flow.

(c) Modified Natural Ion Exchangers

Natural organic ion exchangers can be improved for capacity and selectivity. Carbonic acidic or phosphate functional groups can be found in cellulose-based cation exchangers. Chemically and thermally treating clinoptilolite with diluted acids or salts makes it a more selective radio nuclide sorbent.

(d) Synthetic Organic Ion Exchangers

Adams and Holmes [18] at the National Chemical Laboratory in Teddington discovered in 1935 that organic ion exchange resins might be made like Baekeland’s 1909 “Bakelite” resin. To manufacture “Bakelite,” a rigid, insoluble condensation resin polymer, heat phenols and formaldehyde with an acid or base and remove water [19]. Two phases make up the solution. Adams and Holmes showed that these molecules could interchange hydrogen ions into alkaline solutions and built an acidic cation exchanger using -SO3H. Sulphonation of the end product or starting with a phenol sulphonic acid with the sulphonic acid group were two methods.

(e) Synthetic Inorganic Ion Exchangers

Synthetic zeolites

Hydrated crystalline aluminosilicates of alkali and alkaline earth metals have infinite atomic layers like zeolites. They may also lose and acquire water and interchange atoms without affecting their atomic structure. Zeolites are three-dimensional SiO4 tetrahedra like quartz and feldspar. These forms have four-corner tetrahedra sharing oxygen atoms. The framework is electrically neutral when silicon is the core atom of each tetrahedron, like quartz (SiO2). As triply charged aluminum partially replaces quadric-charged silicon, zeolite forms lack a positive charge. Sodium, potassium, ammonium, calcium, and magnesium help manage charge. Zeolite empirical formulations usually look like

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Clinoptilolite, a common natural zeolite, with the chemical formula

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Oxygen-based structural atoms or cations in the second set of parentheses form the structure’s stiff framework. Exchangeable ions can be substituted with different cations in water without changing the aluminosilicate structure. The process is explained by ion exchange (cation exchange). One singly- or doubly charged solution atom replaces two singly-charged zeolite atoms during exchange.

Polybasic Acid Salts

Adding acidic oxides of IV, V, and VI metals creates acidic salts of multivalent, primarily quadrivalent metals. The precipitation conditions determine their non-stoichiometric composition. Tetravalent metal acid (tma) salts are popular due to their chemical resistance and thermal stability. Cation exchangers generally consist of M(IV)(HXO₄)₂ × 𝑛H₂O, where M(IV) and X can be any element such as Zr, Ti, Sn, Ce, Th, P, W, As, Mo, Sb, etc. These materials feature structured hydroxyl groups with exchangeable H-OH atoms. Their ion exchange capability and metal ion selectivity are high. Amorphous and crystalline Tma salts occur.

Hydrous oxides

Ion exchange materials may be made from newly precipitated trivalent metal ion hydrous oxides.

Ferrocyanides Mn

Water-insoluble inorganic ion exchange agents like ferrocyanides scavenge alkali metals. They are easy to make and frequently utilized in radioactive waste treatment.

1.4.3. Mechanism of Ion Exchange Process

Multiple fixed charges are on ion exchange membranes. Counterions and co-ions are allowed and excluded. Proton ions can easily flow through anion exchange membrane hydration holes. Figure 1 [20] below depicts membrane anion- and cation-exchange functions.

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Figure 1: (a) Anion- exchange and (b) cation-exchange functions [20]

Metal cations are designated by M⁺, anion^-, proton H⁺, and the fixed charges in the membrane by + and -.

Donnan dialysis contacts ions without electricity using ion-exchange membranes. Two electrolyte solutions separated by an ion exchange membrane are electroneutral. Some electrolytes have nonpermeating coions, other counterions. Electrolyte migration stops when counterions pass the membrane and charge separation stops. Donnan dialysis separates feed stream ions by their equilibrium transit across ion-exchange membranes.

As seen here in Figure 2 [20], Donnan dialysis treats aluminum anodizing bath effluent. Sulfate ions and protons easily cross an ion exchange membrane from aluminum sulfate and sulfuric acid into water, forming sulfuric acid. Less acidic aluminum sulfate is recovered or disposed of because its positive charges resist the aluminum cations membrane. Nitric, hydrofluoric, and sulfuric acids may be recovered from stainless steel etching waste and nickel sulfate steel pickling waste. Donnan dialysis works because high-concentration gradients concentrate on products and separate them without electricity.

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Figure-2: Application of Donnan dialysis for separation of sulfuric acid from aluminum sulfate [20]

1.4.4. Kinetics of Ion Exchange Materials

All ion exchange interactions include mass transfer, or diffusion, inside or outside the solution, determining kinetics. All can do it. It’s not an ion exchange limiting step since hydrodynamic turbulence helps. A thick solution zone without convection is the film. Diffusion coefficients characterize film mass movement. Turbulence thins layers. Only mass transfer between fixed groups and counterions can modify the ion exchange rate, depending on the system’s physiochemical parameters. The system would improve with change. Ion exchange does not include complex dissociation or solution ion pairing. These characteristics suggest that counterion diffusion controls most ion exchange, not chemical reactions. Ion diffusion inside the material or across the liquid sheet determines speed. Systemic factors alone affect ion migration in both circumstances. The system must be altered to adjust stage rates. Film diffusion is diffusion via a film, while particle diffusion happens inside a substance. Simple ion exchange relies on a slower process. All bead interdiffusion and film rate-lowering parameters promote film diffusion control, and vice versa. Film diffusion control occurs in systems with high exchange site concentration, low cross-linking, tiny particle size, diluted solutions, and ineffective agitation.

1.4.5. Ion Exchange Capacity (IEC)

Exchangeable ions are measured in meqiv/g or mmol/g membrane dry weight by the IEC. Titration or spectroscopy can quantify NO^[3]− ion concentrations, whereas pH sensors can detect H⁺ or OH⁻ ions in the solution. IEC is commonly titrated by acid/base or Mohr. While the acid/base titration technique may have limitations owing to CO2 poisoning of OH− groups, it may be safer than the Mohr method, which uses hexavalent chromium (CrO[42]−), a known carcinogen. The OH- AEM is exposed to CO2 conditions like ambient air.

When exposed to air or water saturated with air, these groups can convert to HCO³⁻ and change their estimated IEC. Due to little air exposure, this influence may not be noticeable.

Consider testing the membrane IEC in its usual Cl⁻ state during manufacture to prevent pH-related reading anomalies in acid/base titrations. Detecting the AEM IEC in Cl− form requires bringing the AEM to equilibrium in NaNO₃ and acidifying with HNO₃. After dissolving Cl− ions, the solution is adjusted with AgNO₃ using Ag-titrodes until fully converted to AgCl.

Several acid/base titration methods exist for varying strengths and soaking durations. Start by immersing the AEM in a strong base solution like 1 M NaOH to convert it to OH−. To convert it to the Cl− form, immerse it in a strong acid solution at the necessary volume and concentration in step two. After removing AEM, dilute it with DI water. Titrate HCl with standardized NaOH to phenolphthalein.

The Mohr technique converts AEM to Cl− by soaking it in 1 M NaCl. The AEM is washed and adjusted in 0.5 M Na2SO4 to release Cl−. AgNO₃ with a K₂CrO₄ indicator titrates AEM/Na₂SO₄ till the endpoint. The endpoint shows all chlorides precipitated and Ag₂CrO₄ generated.

Human mistake causes erroneous endpoint color change measurements in the computed IEC and other titration procedures. Titrations are complicated without the diluted ion. For AEM titrations to fully convert, powerful bulk solutions like HCl or NaSO4 are needed. The endpoint of acid/base and Mohr titrations is difficult to calculate because the ion exchange ion is less concentrated than the bulk solution. An ISE like a pH probe may detect the endpoint instead of the visible color shift, improving titration accuracy and reducing variability.

1.4.6. Ion Exchange Membrane

Redox flow cell membranes matter. The redox flow system’s membrane selection is often tricky. This membrane should be affordable, chemically stable under acidic environments, mechanically strong, low-permeability to cations and anions, and low-electrical resistance. It must also handle the highly oxidizing positive half-cell electrolyte. When current passes through a redox flow cell, the membrane prevents the positive and negative electrolytes from mixing and the two half-cell electrodes from short-circuiting while enabling ion transfer. Few redox flow cells have reached the market due to membrane difficulties. Ion exchange is facilitated by sheets, ribbons, or tubes. The only difference between resins and membranes is mechanical stress. Because the anion exchange resins are softer and cation exchange resins are brittle, their dimensional stability decreases. Membranes lose strength and dimensional stability without help, affecting mechanical qualities. Linear polymer chains form three-dimensional membranes. The membrane would dissolve in water and form a polyelectrolyte without crosslinking. When they have enough positively charged counter ions and fixed ion functional groups, ion exchange membranes are electrically neutral like resins. Exchange sites like ionic functional groups can form electrostatic connections with oppositely charged ions. The exchange of mobile counter ions with solution-based ions of the same charge is ion exchange. Ion exchange is a reversible, stoichiometric process that swaps ions on the exchanger. Since strong and weak electrolytes dissociate, connection strength influences ion replacement ease [21,22].

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Figure 3 [21] below depicts an ion exchange.

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Figure-3: Ion exchange process [21]

CEMs and AEMs can use IEMs’ selectable characteristics for numerous applications. Desalination, water and wastewater treatment, and producing ultrapure water for food and beverage, pharmaceutical, semiconductor, and power generation are the main commercial uses of IEM. IEMs are used for inorganic acid/base generation, recovery, reversal, and deionization. One method is diffusion dialysis.

1.4.7. Types of Ion Exchange Membranes

Ion exchange membranes are cations or anions depending on the membrane matrix’s ionic functional groups. Cation exchange membranes include negatively charged groups such as _-SO₃⁻, _-COO⁻, and _-PO₃H^-.

C₆H₄O⁻, PO₃²⁻. Only cations like Na+ and chloride are permeable. Anion exchange membranes are _-NH₃⁺ and SR₂⁺.

(a) ANION EXCHANGE MEMBRANE

Semipermeable ionomer anion exchange membranes (AEMs) conduct anions but not gases like hydrogen or oxygen. Reactants are separated around the electrodes and anions are transported for cell functioning.

SR₂⁺ and _-NH₃⁺ exchange membranes. An anion exchange membrane allows cyanide ions to pass, while the polymer binds cation ions. Thus, anion movement but not cation movement. Anion exchange membranes transfer anions and separate reactants via electrodes in electrolytic and fuel cells. A hydroxide anion exchange membrane separates the electrodes in direct methanol fuel cells (DMFCs) and DEFCs.

(b) CATION EXCHANGE MEMBRANE

A cation exchange membrane may separate reactants around two electrodes.

These compounds permit Na⁺ cations but block Cl^- anions. A cation exchange membrane has polymer-bound anions and unbound cations. Thus, cation movement continues but anion movement stops.

1.4.8. Preparation of Membranes

The functionality and chemical composition of the polymer matrix affects ion exchange membrane characteristics. The manufacturing process selects secondary components. This shapes membranes, affecting swelling and transport.

General method of production of ion exchange membrane

Iterative polymer synthesis and post-treatments give membrane selectivity and durability. Most polymer membranes are extruded melted, dry, or wet. Due to its greater production rates, melting and dry extrusion is typically more practical than wet. A polymer melts phase transitions into a colder environment during melted extrusion, forming a thick, isotropic membrane. Latent solvents, which are miscible with polymers at extrusion temperature, can separate secondary phases. Removing solvents produces porosity.

The polymer mixture is dissolved in a volatile solvent before extrusion. A porous anisotropic or isotropic membrane can be made in an evaporation chamber. More membrane shapes are possible with wet extrusion. Batch processing makes commercial polymers differ even within a manufacturer. The “paste method” and membrane casting are not the only membrane-making methods. Paste creates NEOSEPTA® membranes. The process starts with a paste of an ion exchange group-appropriate monomer, divinylbenzene (DVB), a radical polymerization initiator, and finely powdered PVC. A roll of separating film holds paste-covered PVC fabric reinforcing. Monomers are heat copolymerized before adding the base membrane ion exchange group. PVC and ion exchange resin are carefully and continuously woven into ion exchange membranes. Ion exchange membranes are made by casting sulphonic acid groups into base polymers like polystyrene. Cheap components react homogeneously in liquid to form homogeneous sulfonated membranes. Mass production is possible using technology. Normal ion exchange membranes are symmetrical.

Polymerization, polycondensation, and adding cationic or anionic moieties to polymer films provide homogenous ion exchange membranes. Polymer is dissolved, cationic or anionic moieties added, and filmed.

Membrane polymerization monomers include styrene and dimethylbenzene. Cation exchange membranes include slightly acidic carboxylic or very acidic sulphonic acid groups. Chloromethylation and quaternary amination make anion exchange membranes. After adding tertiary ammonium—strongly and weakly basic—amines are classified as primary, secondary, and tertiary. Anion exchange membranes are difficult and expensive to construct.

1.4.8. Advancements in AEM Preparation Methods

Direct polymerization and cross-linking or chemical procedures that change polymers by irradiation or grafting produce the most homogeneous AEMs.

Phase inversion usually entails dissolving membrane precursor solutions in polar solvents, casting them on a plate, and evaporating the solvent to generate an IEM. Most methods need numerous phases and radiation sources like ultraviolet, gamma, or X-ray light or toxic solvents like chloromethyl methyl ether, which is carcinogenic for chloromethylation.

Mixed matrix membranes that incorporate inorganic nanoparticles in organic polymers or pore filling or immersion methods that build polymeric membranes on porous substrates might yield heterogeneous AEM. Similar procedures include pore immersion and filling. Polyethylene, polypropylene, polystyrene, and polyimide are chemically inert and mechanically stable porous polyolefins. The mechanical strength of a porous support and the high ion conductivity of a polymer boost membrane performance. The literature suggests repeated immersion and pouring stages to make high-IEC anion and cation exchange membranes. Synthesizing AEMs with multiple small ion channels on a porous substrate increases their OH- -conductivity.

The wide range of inorganic nanoparticles and organic polymers that may be mixed gives heterogeneous membranes great promise. Inorganic nanoparticles such as metal ions, oxides, silica, imidazolium-functionalized silsesquioxane, graphene oxide, and carbon nanotubes are helpful. Ion conductivity, thermal, chemical, and mechanical stability improve with the inorganic phase. Organic phases increase membrane flexibility. Making homogenously mixed matrix membranes with sol-gel techniques requires evenly scattered inorganic nanoparticles in the organic phase. AEM with high IEC and mechanical strength may be made using heterogeneous membranes with inorganic nanoparticles or porous supports. The range of porous substrates and inorganic nanoparticles permits membrane-tuning research for numerous applications.

1.4.9. Desired Properties of AEM

AEMs for energy storage are well-developed. Electrolytes and fuel must pass through membranes to flow anions. AEM efficiency determines fuel cell and battery flow efficiency. A commercially viable AEM must have high anion conductivity, chemical stability, mechanical strength, and low cost. High-current membranes must have significant ionic conductivity. Increased membrane cationic groups degrade mechanical characteristics due to water absorption. Improve mechanical qualities by modifying membrane composition. Good mechanical and thermal stability, anionic conductivity, cheap cost, and 50-80 gm thickness are essential for practical AEMs. Electrical resistance to electrons is crucial.

1.4.10. Transport Mechanisms in AEM

The Grotthuss mechanism, diffusion, convection, and surface site hopping transport hydroxide ions across AEMs. The Grotthuss process transfers most hydroxide ions via water AEMs. Hydroxide ions travel across water molecules by creating and breaking covalent bonds, according to Grotthus [23]. Transporting hydroxyl ions needs concentration or potential gradient. Hydroxyl ions convert water molecules across cell membranes. Hoping across surfaces with hydroxyl anions Quaternary ammonium groups are secondary transport across the membrane, where fixed charges make water a persistent dipole.

1.4.11. Chemical Stability of AEM

Chemical stability limits AEM development. In acidic and oxidative conditions, membrane polymer backbone and cationic groups break down. Most polymer backbone breakdown happens under severe oxidative or hydroxyl conditions. VDF and PVDF copolymer AEMs degrade in acidic and oxidative conditions. Operating membranes discolor and lose mechanical strength due to quick decomposition. Therefore, AEMs should not start with VDF and PVDF. AEMs with radiation-induced cationic moieties on polysulfones and fluorocarbons improve polymer backbone chemical stability.

1.4.12. Mechanism of Degradation of Cationic Group

Phosphonium and ammonium are cationic. Sulfur dioxide, Pyridinium, guanidinium, and imidazolium use AEM anion-exchange sites. Degradation includes removal or replacement. Quaternary ammonium cleavage after OH- attack is E2 elimination or Hoffmann degradation. Alkenes, amines, and water are produced by hydroxyl ions attacking ammonium beta-hydrogens.

Elimination occurs when large groups attach quaternary ammonium group E. This decrease affects ammonium’s alpha or beta carbon. Hydrogen ions attack the ammonium methyl group, producing an alkene and amine. Hydroxyl attacks the quaternary ammonium group’s alpha-hydrogen, causing nucleophilic substitution (SN2) breakdown. Make alcohol and amine. AEMs have limited ionic conductivity because too unstable cationic groups, limiting electrochemical device application and longevity.

1.4.13. Effect of Crosslinking

Cross-linking stabilizes AEM chemicals. The restricted free space between major chains makes hydroxide ions’ assault on cross-linked macromolecules’ cations tougher. Ni J et al.’s [24] unique self-cross-linked poly(ethersulfone) AEMs were alkaline- and dimensional-stable. Ionic conductivity dropped a little from 20 to 80°C in cross-linked copolymer membranes submerged in 1M NaOH for 30 days. In situ cross-linking 1-vinyl-3-methylimidazolium iodide with styrene and acrylonitrile and anion-exchanging with hydroxide ions produced cross-linked AEMs from alkaline imidazolium type ionic liquids. Ion-exchange capacity was 2.19 in mol g^-1 and membrane conductivity was 83 mS cm^-1. Poor mechanical qualities stopped fuel cells from employing membranes.

1.4.14. AEM Fabrication Methods

Grafting, plasma, block, copoly, solution casting, sol-gel, and supported composite AEMs are important AEM fabrication procedures.

(a) AEMs prepared by paste method

Commercial AEMs like Neosepta are paste-based. Styrene and mono vinyl monomers are in paste. Continuously coating a backing fabric and covering both sides with PVA/PTFE separating films produced vinyl pyridines, chloromethyl styrenes, divinyl monomers (such as divinyl benzene and dimethcrylate), initiators of polymerization, and reinforcing polymers. After melting and fusing PVC with the composite, the monomers copolymerized into a film. Another method polymerizes cloth between two plastic sheets or glass plates utilizing vinyl monomers, peroxide, additives, and linear polymers.

(b) AEM polymerization of monomers

Monomers have functional groups that can become co-polymerized cations to form AEMs. The copolymer of 4-vinyl pyridine and divinyl benzene. Glass plates with inert polymers and directly cast membranes beef up membrane mechanical strength. This can be quaternized using alkyl halides or tertiary amines. Good electrical resistance and ion exchange capacity, but mechanical features make these membranes unsuitable for independent applications. Net backings with glass plates on both sides and linear polymers like polyvinylchloride and polyethylene styrene butadiene rubber can reinforce styrene-divinylbenzene membranes. Wu et al. [25] employed solvent-free techniques. After dissolving Bromo methylated poly (2,6-dimethy1-1,4-phenylene oxide) (BPPO) in monomers, trimethylamine was utilized for in situ polymerization and quaternization. Monomers lacking functional groups provide a block for thin film slicing. Styrene was block-polymerized using DVB and benzoyl peroxide. Chloromethylation and quaternization gave membranes anion-exchange capacity. AEMs may be synthesized easily by quaternizing vinyl pyridine with an alkyl halide instead of styrene. The membranes’ homogeneity provided AEMs with great electrochemical characteristics. Cutting a huge polymer block demands precise tools. This technology cannot mass-produce membranes in a lab.

(c) AEMs prepared by the solution casting method

Simple solution casting works for soluble polymers, mixes, and copolymers. It dissolves polymer and functional group insertion by chloromethylation, film casting, and quaternization. Hwang et al. [26] solution cast, chloromethylated, and quaternized a polystyrene-polyphenylene sulfide sulfone block copolymer to make the AEM. AEMs were made without harmful substances using bromination and 4-bromomethylation. NBS was dissolved in dichloroethane or tetrachloroethane. The bromination process was harmless. Thin Bromo methylated polymer films formed after quaternization. The quantity of NBS controls bromination.

(d) AEMs prepared by grafting method

Radiation grafting benefits from adaptability. Reaction circumstances can quickly alter membrane composition. The polymer backbone was covalently grafted with side chain grafts to generate a branched copolymer. Polymer weight gain measured by grafting. Simple and inexpensive radiation-induced graft copolymerization can polymerize incompatible monomers. Radiation grafting monomers onto polymer skeletons using UV, plasma, gamma (from Co-60), and electron beams. Vinyl pyridines, glycidyl methacrylates, and vinyl monomers like VBC on polymer films formed AEMs via radiation grafting. These grafts were created by directly irradiating monomers onto PE, PP, PVDF, ETFE, FEP, and PTFE substrates with UV or plasma radiation. Amination and ion exchange made anion-exchanging membranes.

(e) Plasma polymerization

Slow discharge plasma polymerization is ionizing radiation-like chemical vapor deposition. Ionization, dissociation, and electron-induced excitation occur in plasma grafting. An intriguing plasma grafting feature in which plasma species, ions, and neutral particles create functional group bonding sites on polymers. Active species create macromolecular radicals by breaking the polymer matrix’s initial chemical bonds, causing graft copolymerization.

(f) Pore filling

For liquid separation, Yamaguchi [27] developed pore-filling IEMs with minimal swelling and great selectivity in 1991. The pore-filling approach requires a mechanically strong and chemically inert porous substrate for IEM generation. The holes cannot expand in soft electrolytic polymers. Polyacrylic acid. HDPE, PP, and porous alumina are porous substrates. Keeping concentrated ionomer solutions with the right viscosity on porous membranes keeps them within. With this procedure, a polymerized and quaternized porous PE using VBC monomers and amines can be placed. Ambient temperature conductivity was 38.1 mS cm-1 for trimethylamine membranes. Membranes now have better electrochemistry and less swelling. Pore-filled composite membranes from alkaline fuel cells and non-aqueous vanadium redox flow batteries can be employed. In fuel cells and redox flow batteries, thicker pore-filled membranes reduce liquid fuel and ion permeation. Mechanical strengthening with inert polymers and quaternization with long carbon chain amines make alkaline membranes more robust. However, redox systems need chemical stability adjustments. Pore-filling produced organic-inorganic composite membranes. Take an example: After soaking in 2M sodium hydroxide aqueous solution, PAN ultrafiltration membranes were installed in filtration cells. Under controlled pressure, the filtration cell filtered PVA-GO dispersion. The membranes were removed and oven-dried to generate a “pore-filling” composite membrane. Porous nanohybrid membrane swelling studies indicated decreased swelling. Putting together GO molecular dispersion in PVA enhanced nanohybrid membrane affinity for aromatic chemicals, boosting toluene/n-heptane pervaporation. Controlling membrane separation is simple with pressure, filtering time, polymer, and GO concentration.

1.4.15. Applications of AEMs

Sol-gel is excellent for producing organic-inorganic hybrid membranes because of its composition flexibility. The polymer matrix’s inorganic components increase membrane chemical and mechanical characteristics. Sol-gel links organic and inorganic molecules to produce composite membranes. Electrochemical qualities come from organic domains, whereas mechanical strength comes from inorganic domains. The low-temperature technique achieves high molecular compatibility between organic and inorganic components. Colloidal particles in liquid produce soils, whereas hydrogen-bonded polymer chains form gels. Sol-gel methods generate three-dimensional networks by hydrolyzing metal alkoxides into hydroxyl groups and polycondensation. Sol-gel often forms M(OR)_n alkoxide precursors in low molecular weight solvents. M is a network-forming element (Si, Ti, Zr, Al, B, etc.) and R is an alkyl group (C_xH_2X+1). During condensation and hydrolysis. Water and alcohol are eliminated. This approach created hybrid polymer-silica membranes by creating an inorganic network with an organic polymer and then interpenetrating organic polymer and metal oxide networks. These organic polymers can bind hydrogen to form organic-inorganic hybrid membranes: poly (2-methyl-2-oxazoline), poly (vinyl pyridines), poly (methyl methacrylate), poly (vinyl acetate), polyamides, and Nafion for anion exchange, alkoxysilane or quaternary amino groups are used. Quaternization and sol-gel copolymerization of γ-MPS with VBC create an anion-exchange hybrid membrane interacting with monophenyl triethoxysilane. PET fabric helps absorb water and is strong.

1.4.16. Fuel Cells

Fuel cells are modern, eco-friendly, and efficient energy converters. Fuel and oxidant chemical energy may be directly converted into DC electricity with just water and heat waste. Fuel cells avoid heat and mechanical effort, which most power-generating systems need, hence they are not restricted by Carnot efficiency. Fuel cells, unlike batteries, need a constant supply of reductants and oxidants to remove SO_X, NO_X, CO₂, and CO. Sir William Robert Grove proposed fuel cells in 1839. Commercialization requires hydrogen storage, component materials, long-term durability, and system performance concerns. Francis Bacon researched fuel cells in the 1930s. Molten KOH electrolytes created the first alkaline fuel cell in the 1950s. NASA used alkaline fuel cells for Apollo in the 1960s.

The basic physical structure of a fuel cell

Fuel cells use electrolytes and anodes/cathodes. Fuel travels to the anode, oxidant to the cathode. Water-wasting electrochemical methods create power. The approach has drawbacks, including using liquid electrolytes. Carbon poisoning and shunt currents precipitate liquid electrolyte carbonate.

The chemical explanation for carbonate precipitation follows.

Dissolution of CO₂ in the electrolyte

Illustrations are not included in the reading sample

Carbon dioxide dissolves in water, forming carbonic acid.

Formation of Carbonate Ions

Illustrations are not included in the reading sample

Carbonic acid dissociates into bicarbonate (HCO₃⁻) and carbonate (CO₃²⁻) ions.

Precipitation of Carbonates in Electrolyte Solution

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In potassium-based electrolytes, carbonate ions react with potassium ions to form potassium carbonate (K₂CO₃) precipitate.

High-pH electrolytes absorb even trace carbon dioxide, lowering conductivity. Thus, fuel and oxidant must be ultra-pure hydrogen and oxygen. The cost of liquid electrolyte alkaline fuel cell power output depends on high-purity oxygen.

1.4.17. Fuel cell classifications

Electrode-ion interactions are controlled by fuel cell electrolytes and fuels. Alkaline, phosphoric acid, molten carbonate, and solid oxide fuel cells are mentioned. The latter impacts fuel cell operating temperature, material physicochemical and thermomechanical characteristics, and electrolyte selection. High vapor pressure and rapid deterioration at higher temperatures restrict aqueous electrolytes to 200°C or below.

(a) AFC (alkaline fuel cell)

Alkaline fuel cells (bacon fuel cells) use KOH or another alkaline aqueous solution as its electrolyte below 100°C. They operate as illustrated in Figure-4 [22] below, electrochemical reactions create electricity by connecting fuel and air electrodes to hydrogen and oxygen, respectively.

Oxidizers include pure oxygen or air and fuels like hydrogen. Carbon dioxide pressure affects aqueous electrolytes; hence reactant gases should not include it. Concentration enhances electrolyte properties by decreasing water activity and making interactions simpler. Reducing water vapor pressure makes process water harder to evaporate and remove, therefore cell parameters and operating circumstances dictate concentration.

The cathode reaction is O₂ + 4H⁺ + 4e^- → 2H₂O, while the anode reaction is H₂.

General Reaction: 2H⁺, 2O₂, 2e^- produce 2H₂O.

Illustrations are not included in the reading sample

Figure-4: Alkaline Fuel Cell [22]

Applications for AFCs:

- Fuel-cell boat and cab.
- A generator-powered golf cart.
- Electric automobiles, forklifts.

Advantages of AFCs:

- Alkaline technology has a long history of use in space and underwater applications.
- Durable and strong.
- AFC Energy has improved its successful alkaline fuel cell technology to reduce the total cost of ownership.

Disadvantages of AFCs:

Because the electrolyte is CO₂ sensitive, pure H2 was used as fuel.

Natural air oxidizes, therefore removing CO₂.

(b) PEMFC

Due to their low starting temperature, ease of handling, high power density, and energy conversion efficiency, proton exchange membrane fuel cells (PEMFC) are being studied for portable and automotive applications.

An ion exchange membrane electrolyte conducts proton well in this fuel cell. Fluorinated sulfonic acid polymer might be the membrane. This fuel cell contains water, so it doesn’t corrode. The PEMFC anode and cathode generate energy through electrochemical reactions:

The reaction at the anode is Illustrations are not included in the reading sample.

The reaction at the cathode is Illustrations are not included in the reading sample.

The cell reaction is Illustrations are not included in the reading sample.

Hydrogen ions can cross the polymer electrolyte membrane, but fuel and electron transport are limited.

AEMFCs, which employ AEM as the polymer electrolyte and hydroxide ions (or other anions) as charge carriers instead of protons, have attracted interest in recent decades. Alkaline medium simplifies fuel oxidation and oxygen reduction. Cobalt and nickel catalysts can extend fuel cell lifespan and minimize cost in alkaline environments due to their low corrosion. Low fuel crossover, high fuel cell efficiency, and fuel flexibility are further AEMFC benefits.

Fuel cell processes in ANIFCs and typical AFCs are similar: anode reaction: Illustrations are not included in the reading sample

The cathode reaction occurs when Illustrations are not included in the reading sample is applied.

Total response: Illustrations are not included in the reading sample

Carbonate/bicarbonate (CO₃²- /HCO₃-) formation from OH- ions reacting with CO₂ pollution in the oxidant gas stream blocks electrode pores and destroys active layers in conventional AFCs. Since the electrolyte with cationic groups is solid, an AEM without metal cations prevents carbonate or bicarbonate salt production.

REDOX FLOW BATTERIES

Redox flow batteries (RFBs) are 1970s electrochemical energy storage technology. Redox flow batteries employ two electrolyte reservoirs and a series or parallel stack of electrochemical cells for inert processes. Pumps move electrolytes via stack conductive materials. A cell ion exchange membrane separator separates electrolyte solutions from the anode and cathode reservoirs while allowing ions to diffuse.

Redox couples are electrochemically reduced and oxidized in charge/discharge cycles. Charge carriers are transmitted via the IEM in electrical neutrality. Zn-Br, polysulfide-bromide, iron-chrome, and VO₂+/V₃+ are redox couples. RFBs like vanadium redox flow batteries (VRFBs) because the catholyte and anolyte solutions contain the same metal cation. Reversible membrane vanadium ion regeneration prolongs electrolyte solution life. VRFB technology is infrequently employed but has a long life, easy redox reactions, and independence from power and energy ratios. VRFB electrolytes must be often regenerated due to active species crossing the IEM, reducing reliability. Vanadium ions and charge carrier protons boost CEMs’ inherent cation permeability. CEM-built VRFBs have poorer coulombic efficiency. Few studies assess VRFB AEMs. AEMs impede vanadium ion passage because of their fixed positively charged groups. While protons carry some charge, sulfate carries most. Perfluorinated CEMs like Nafion membranes will survive continuous charge/discharge cycles, whereas AEMs will not. Systemic membranes for RFB are sluggish to develop. Tests on single cells included membrane efficiency, catholyte breakdown, and active species crossover. Pumped hydro, compressed air, flywheels, fuel cells, and redox flow batteries store energy. Redox flow batteries are excellent for medium to large-scale energy storage due to their high energy efficiency, low initial cost, and low lifespan costs (no site required)

Figure 5 [21] shows a vanadium redox flow battery.

Illustrations are not included in the reading sample

Figure-5: Redox flow battery [21]

When electricity is applied to terminals, half-cell electrolytes charge. Electrons bridge redox species to discharge chemical energy into electricity. In conclusion, the system’s power and energy capacity relies on the electrode area, stack cell count, electrolyte volume, and active redox species concentration. Redox flow batteries work like regenerative fuel cells. The University of New South Wales's all-vanadium redox flow battery is the most talked-about because of its long cycle life and energy efficiency (over 80% in big installations). Iron/chromium, iron/titanium, and polysulfide bromine redox flow batteries struggle with membrane formation and electrolyte cross-contamination. To avoid electrolyte cross-contamination, all vanadium flow batteries employ the same vanadium element in both half cells. Required capital is less, reducing waste, maintenance, and operating burden. Even in harsh areas, underground electrolyte storage tanks decrease footprint and temperature fluctuations. Redox flow EV batteries may be charged manually or automatically at stations, increasing their attractiveness. The early vanadium redox flow batteries (VRBs) used sulphuric acid in both half-cells, with the negative half-cell having the V₂+/V₃+ redox couple and the positive half-cell the VO₂+/VO₂+ pair. Reduce V3+ when charging the positive electrode oxidizes VO2+ to VO2+, negative electrode creates V₂+. These cells discharge reverse reactions. Vanadium ion concentration is normally 2 M or less in a wide temperature range functioning. The solubility limit of V(II) and/or V(III) ions in the sulphuric acid supporting electrolyte below 5 °C is 25 Wh/kg. This concentration indicates V(V) ion stability above 40 °C. Many harsher places with subzero winters require lower electrolyte concentrations. Vanadium sulfate concentrations as low as 1 M may be needed to avoid precipitation, reducing energy capacity. Despite substantial membrane material research since 2005, Li et al. [28] and Schwenzeretal’s [29] G1 VRB membrane assessments may not apply to G2 VRB systems. Choosing the right redox flow cell membrane is crucial. An inexpensive membrane with strong mechanical qualities, low electrical resistance, and resistance to the highly oxidizing positive half-cell electrolyte is desirable. A good membrane should also prevent water from preferentially moving from one-half cell to the other, which would flood one and dilute the other. Membrane concerns keep many redox flow cells from commercialization. Ion exchange membrane techniques Ostwald established in 1890 after realizing that semi-permeable membranes impermeable to their cations or anions might be impermeable to any electrolyte. Fluids are separated by several sheets, ribbons, and tubes as ion exchange membranes. The only difference between resins and membranes is mechanical stress. Because cation and anion exchange resins are brittle and soft, they are dimensionally unstable. Membranes without a supporting material have these mechanical characteristics. Three-dimensional cross-linked linear polymer chains form membranes. Water will dissolve the membrane into a polyelectrolyte if not cross-linked. Like resins, ion exchange membranes feature fixed ion functional groups and enough oppositely charged counter ions to neutralize the exchanger. Juda and McRae’s stable, highly selective, low electric resistance membrane (Ionics Inc., Cambridge, MA, USA) was rarely utilized before 1950 [30]. Recent membrane technology development focuses on batteries.

2. LITERATURE REVIEW

This review discusses existing anion exchange membranes (AEMs), polymer topologies, and production processes. We highlight the limitations of current AEM characterization methods. AEMs for high temperatures and acidic conditions are the subject of anion exchange membrane fuel cell and water electrolysis research. AEM head groups include ruthenium, quaternary ammonium, and phosphonium. Stability and valence make metal cation head groups promising for AEM. Using “rational polymer architecture,” AEMs with ion channels and chemical stability may be made. Since you may change the polymer-to-porous support or nanoparticle ratio, heterogeneous membranes with inorganic nanoparticles or porous supports are promising. AEM head groups, which promote chemical stability, and an optimized polymer structure with ion channels and better membrane characteristics from porous support or nanoparticles in heterogeneous membranes should be studied further.

The ion-exchange membrane of redox flow batteries impacts performance and cost. Most materials are “stolen” for other purposes. Next-generation membrane/separator materials must account for complicated species movement when flow batteries attain greater current densities. We explore the vanadium redox flow battery, its components, membrane, and separator technologies.

Recent vanadium redox flow battery membrane technology advances

As renewable energy consumption develops, large-scale, inexpensive, and effective energy storage technologies are needed to overcome their intermittent nature. Recent interest has focused on the vanadium redox flow battery (VRFB) for large-scale energy storage. The membrane impacts VRFB’s cyclability and profitability. The membrane divides positive and negative half-cells and conducts ions to prevent vanadium ions from mingling. Cheap, chemically stable, low swelling ratio, strong ionic conductivity, low water absorption, area electrical resistance, vanadium, and polyhalide ion permeability are suitable membrane properties. Ion exchange and non-ionic porous membranes are well-studied. Characterization and development of commercial and innovative VRFB membranes. It analyzes many membrane product production processes. Academics and industry specialists interested in VRFB system development and dynamic modeling sets may find a thorough overview table of the new membranes’ production, cost, and features. After that, membrane research opportunities and problems are discussed.

Redox Flow Battery Membranes

Renewable energy integration into the power grid has prioritized large-scale energy storage. Redox flow batteries store medium-to-large power wells. However, redox flow batteries are too expensive to use widely. Redox flow batteries’ performance and profitability depend on the membrane. Despite electricity traveling across the membrane dividing positive and negative electrolytes, ions complete the circuit. Ideally, membranes have strong ionic conductivity, low water input, chemical, and thermal stability. Also crucial is ionic exchange. This study discusses all-vanadium redox flow battery membrane literature, the most prevalent.

Ion exchange membrane vanadium VRBs

The vanadium redox flow battery (VRB) is popular for its large energy storage capacity. To regulate voltage, batteries use IEMs. They prevent positive and negative electrolytes from mixing yet let ions complete the circuit when the current flows. For clarity, this review includes all essential IEM features. We’ll describe the IEM’s purpose and the need for more sophisticated options after a high-level VRB debate. Finally, we will discuss VRB IEMs and content recommendations.

Fuel Cell ACE Membranes Improvement

Maurya et al. [31] study electrochemical energy systems and AEM synthesis. Selective anionic transport and decreased cationic species crossover in fuel cells and redox flow batteries are AEM benefits. New polymer designs and excellent chemical stability and conductivity are also discussed in the paper.

Recent Fuel Cell Anion Exchange Membranes Advance

This thorough fuel cell AEM study by Chen et al. [32] covers all elements. They study approaches to increase chemical and mechanical stability while keeping high ionic conductivity to address polymer endurance in severe alkaline environments. Researchers predict future AEMs to rely heavily on polymer design, which might lead to longer-lasting fuel cells and greener residential and commercial electricity.

New Ion Exchange Membrane Fuel Cells

Recently, Vedarajan et al. [33] created AEM fuel cells. The authors credit performance over 3 W cm⁻² to enhanced membrane characteristics, binder materials, and cationic species adsorption knowledge. Alkaline AEM fuel cell technology must overcome stability difficulties and run for over 5,000 hours to be commercialized; the review found.

Redox Flow Batteries’ Anion Exchange Membrane Chemical Stability

Recent research resolved a key chemical stability issue for redox flow battery AEMs. AEMs may inhibit vanadium ion crossing due to the Donnan effect, although their oxidative tolerance is unknown. Numerous studies have explored membrane disintegration methods, including Fenton’s reagent treatment and immersion in VO₂⁺ solutions. Membrane lifespan depends on polymer backbone and quaternary ammonium group breakdown. AEMs in redox flow batteries require a chemical stability study.

Fuel Cell Anion Exchange Membranes: Analysis

In 2022, researchers intensively studied AEM fuel cell use. Also explored are alkaline fuel cells and their transition to solid polymer electrolyte membranes. It highlights AEMs’ decreased fuel crossover, enhanced basic media reaction kinetics, and low operating temperatures. Selectivity, stability, and operating environment durability are membrane design assessment challenges. These obstacles must be overcome for AEM-based fuel cell research and commercialization.

To increase AEM performance, polymer chemistry for alkaline fuel cells and redox flow batteries has been investigated. Studies reveal that poly (phenylene oxide) and poly (aryl piperidinium) backbones improve ionic conductivity and chemical stability. Li et al. [34] showed that steric hindrance makes polymers hydroxide-resistant, extending membrane life. Innovative cross-linking technologies boost mechanical strength and ionic transport efficiency. Researchers are studying hybrid materials containing zirconium phosphate and graphene oxide to improve conductivity and decrease adverse effects. Improved polymer chemistry will reduce breakdown routes and maintain strong hydroxide ion conductivity, making AEMs more suitable for large-scale energy applications.

Quaternary Ammonium Stabilizes Acidic Anion Exchange Membranes

Zhang et al. [35] examined nucleophilic attack and Hofmann elimination, which destroy QA-based membranes at high pH. Researchers have investigated cationic groups including guanidinium, imidazolium, and phosphonium to improve stability. They observed that big QA groups with steric hindrance made membranes hydroxide-resistant and durable. Hydrophobic polymer backbones like polybenzimidazole reduce water absorption and swelling, stabilizing. These findings imply that future AEM technology will focus on innovative cation architectures that can resist extreme acidic conditions without losing ionic conductivity.

Zinc-iron Redox Flow Batteries Aid Anion Exchange Membranes

Novel and environmentally friendly zinc-iron redox flow batteries (ZIRFBs) store large amounts of energy. Customizing ZIRFB AEMs to prevent zinc dendrite development and increase charge-discharge efficiency has been studied recently. AEMs with customized ion selectivity reduce side reactions and preserve ionic conductivity with altered pore morphologies, Wang et al. [36] observed. Hydrophilic coatings, especially sulfonated polymers, minimize fouling and degradation, increasing membrane life. These improvements make ZIRFBs cheaper, enabling their use in renewable energy storage.

Improving Anion Exchange Membrane Ionic Conductivity with Nanocomposite Materials

Recent research has examined improving AEM ionic conductivity and mechanical characteristics using nanomaterials. Due to water retention and swelling decrease, nanocomposite AEMs containing graphene oxide, silica nanoparticles, and metal-organic frameworks transport hydroxyl ions better. Zirconium-based MOF-infused membranes showed 40% greater ionic conductivity and better chemical stability than standard AEMs in 2024, according to Yang et al. [37] Nanomaterials restrict direct hydroxide assault on quaternary ammonium groups, reducing breakdown pathways. This research implies nanocomposite AEMs might be next-generation redox flow batteries and high-efficiency alkaline fuel cells.

Making Commercial Anion Exchange Membranes Cheaper

AEM technology has evolved, but its high cost hinders its broad use in fuel cell and energy storage applications. Recent economic studies have studied cost-cutting technologies including membrane production, scalable manufacturing, and low-cost polymer synthesis. Patel et al. [38] studied bio-based polymers as long-term petroleum alternatives. Roll-to-roll processing streamlines mass production, lowering manufacturing costs. Stable functional groups save money on materials without impacting performance. These include pyridinium and phosphonium. These approaches show AEMs’ efficiency and cost. Soon, alkaline fuel cells and redox flow batteries may be available.

Structure Changes Enhance Anion Exchange Membrane Selectivity

For AEM development, strong ionic conductivity and selectivity must be matched to avoid ion crossing. Research on membrane design alterations seeks this equilibrium. Lee et al. [39] minimized significant anionic species and maintained strong hydroxide conductivity with multi-layered AEM structures with thick inner layers. Phase-separated topologies with hydrophobic polymer backbones for mechanical strength and hydrophilic ionic clusters for ion mobility have been investigated. Research demonstrated that these structural modifications can greatly minimize crossover issues in redox flow batteries while preserving stability. Using asymmetric membranes with precise pore diameters increases selectivity, efficiency, and side reaction reduction. These data show that membrane design optimizes AEM energy conversion and storage.

Water Uptake Enhances AEM Performance

Hydroxide ion transport and AEM membrane flexibility depend on water content. However, excessive water absorption can cause membrane swelling and mechanical instability, limiting performance. Tan et al. [40] studied mechanical strength and ionic conductivity with regulated hydration in 2023. Researchers showed that hydrophilic-hydrophobic block copolymers boost water retention without edema. Polymer cross-linking and nanofillers like silica and titanium dioxide are studied for water management. Research shows that good ionic conductivity and dimensional stability need hydration. Next-generation AEMs must be designed for real-world durability and performance using these insights.

Different Cationic Functional Groups Stabilize Alkaline

Quaternary ammonium (QA) groups, utilized in AEMs, break down at high pH. Scientists have examined phosphonium, guanidinium, and imidazolium as hydroxide-resistant cationic groups. Kumar et al. [41] found that phosphonium AEMs in alkaline fuel cells have substantial ionic conductivity after 1000 hours. Membranes functionalized with imidazolium have delocalized charge distribution, reduced nucleophilic attack, and increased chemical stability. These novel cationic groups may improve AEM durability, making fuel cell and battery technologies cheaper.

Biomaterial-Based Renewable Energy AEM Research

Biomaterial-based AEMs are being studied as a green energy storage alternative. Zhao et al. [42] studied shellfish-derived chitosan AEM production. Biodegradable modified chitosan membranes were ionically conductive and had less environmental effect than synthetic polymer AEMs. Cellulose-based AEMs have potential mechanical strength and alkaline stability. Natural polymer-based membranes assist global energy goals as an eco-friendly alternative to AEMs. To increase biomaterial-based AEMs’ ionic conductivity and longevity, chemical modifications and hybrid material integration will be studied.

Life and Operation of Redox Flow Battery AEM

Optimizing redox flow battery performance requires understanding how operational circumstances impact AEM lifespan. Temperature, pH, and electrolyte composition impact membrane breakdown, according to Singh et al. [43]. Ionic conductivity decreased with time because high temperatures dissolved functional groups, research shows. Vanadium ions fouled vanadium redox flow battery membranes, lowering efficiency. Scientists advocate fluorinated and antioxidant-coated surfaces to decrease these factors. Research shows that pH stability and ion crossing control impact membrane longevity. These insights are needed to make AEM-based redox flow batteries cheaper.

Advanced Anion Exchange Membranes: Future Machine Learning

Machine learning and material science have accelerated the identification of high-performance membranes, transforming AEM. Recent AI research predicted alkaline polymer stability, ionic conductivity, and breakdown. Study: Patel et al. [44]. Machine learning algorithms discovered polymer backbones with superior hydroxide conductivity and chemical resistance from massive experimental data and computer simulations. Ion transport efficiency has improved by using AI in molecular modeling to design membranes with appropriate hydrophilic-hydrophobic phase separation. Data-driven membrane development speeds up and improves efficiency. This allows energy-efficient and long-lasting fuel cells and redox flow battery AEMs.

Better ion exchange membranes using metal-organic frameworks

MOFs, which are becoming common, increase AEM conductivity and mechanical stability. Research shows that clear nanoporous channels produced by MOFs in polymer matrices improve hydroxide ion transport. An example: Wang et al. [45]. MOF-modified AEMs reduce swelling and heat better than normal membranes. Ionic selectivity and fuel crossover reduction are improved by MOF cationic group functionalization in redox flow batteries. Future hybrid MOF-polymer membrane syntheses may bridge lab-performing and commercially feasible AEMs.

Compare Alkaline Fuel Cell Operating Conditions to AEM Lifespan

The real-world membrane deterioration limits AEM-based alkaline fuel cell application. Environmental factors affect AEM lifespan, according to Liu et al. [46]. A study indicated that cationic functional groups decayed faster, and ionic conductivity decreased after extended high-temperature contact. Humidity swelled membranes and broke them. These concerns are being addressed by researchers designing thermally stable polymer backbones and moisture-regulating chemicals. To design AEMs for demanding industrial energy applications, understand these operational consequences.

Ion and anion exchange membrane efficiency

Ion exchange capacity measures electrochemical AEM performance. Zhang et al. [47] studied membrane stability and high IEC. IEC increases ionic conductivity, water absorption, swelling, and mechanical strength drops. The study suggested cross-linked polymer topologies that balance IEC and dimensional stability for excellent ion transport and structural stability. To increase long-term performance, new cationic functional groups with better alkaline resistance were investigated. These findings indicate that high-efficiency redox flow batteries and fuel cells need AEMs with fine-tuned IECs.

The Greener Synthesis of Anion Exchange Membranes

Green AEM synthesizing approaches are being studied for environmental sustainability. As per Kumar et al. [48], lignin-derived polycations are renewable and biodegradable for membrane production. Solvent-free synthesis lowers polymer processing waste. Sustainable manufacturing practices lower AEM costs and environmental impact. Environmentally benign synthesis advancements may speed up AEM commercialization, supporting global energy storage technology sustainability goals.

Nanocomposite Reinforcement Strengthens Anion Exchange Membranes

Designing AEMs with long-term mechanical integrity is tough. Recent research incorporates nanocomposite fillers including graphene oxide (GO), silica (SiO₂), and carbon nanotubes (CNTs) to strengthen polymeric AEM structures. Park et al. [49] found good ionic conductivity and mechanical strength in GO-based AEMs. Nanocomposites distributed ionic domains over the membrane, boosting anion transport and avoiding swelling. CNT-reinforced membranes resist oxidative breakdown, therefore alkaline fuel cells use them. The findings show that nanotechnology is crucial to energy-use AEM reliability.

To Cross-Link Anion Exchange Membranes for Acidic Stability

Alkaline resistance makes AEMs difficult to use in industry. Cross-linking may increase membrane longevity without altering ionic conductivity. Sharma et al. [50] examined divinylbenzene and polyethylene glycol diacrylate effects on membranes. Controlled cross-linking minimized water absorption and swelling, limiting mechanical degradation. Cross-linked AEMs’ hydroxide-resistant degradation enhanced redox flow battery lifetimes. This research shows how cross-linking chemistry improves electrochemical energy storage membrane architecture.

Functionalized AEM Polymer Backbones Improve Ionic Conductivity

Polymer backbone choice greatly affects AEM efficiency. Chemical stability makes hydrocarbon-based polymers popular. This is poly(arylene ether sulfone). Functionalizing polymer backbones with complex cationic groups improved ionic conductivity, according to Wang et al. [51]. Imidazolium-functionalized polyphenylene membranes enhanced anion transport by separating ionic and non-ionic regions. High-temperature fuel cells benefit from thermally stable polybenzimidazole (PBI) membranes. Results reveal that polymer functionalization improves operating longevity and AEM efficiency.

Advanced Electrochemical Materials for Future Redox Flow Batteries

Popular redox flow battery hybrid membranes integrate organic and inorganic polymers to improve AEM performance. In 2023, Chen et al. [52] examined polymeric AEMs containing ZrO₂ and TiO₂ nanoparticles. Hybrid membranes, essential to successful redox flow batteries, decreased vanadium ion crossing without affecting ionic selectivity. Inorganic particles increase membranes’ oxidative stability of membranes, extending their lifespan. Results demonstrate hybrid AEMs generate durable, high-performance energy storage membranes.

Recycling AEMs Energy Systems

The focus on sustainability in energy research has highlighted AEM recyclability. Recently discovered membrane rejuvenation technologies cut waste and manufacturing costs. In 2024, Patel et al. [53] researched oxidative and alkaline treatments to chemically revive aged AEMs. The study demonstrated polymer backbones may be reprocessed without severe performance loss. Includes polystyrene membranes. The AEMs produced from cellulose and lignin may biodegrade. The results imply that future AEM research should focus on environmental effects and performance to produce more sustainable electrochemical energy storage devices.

3. MATERIALS & METHODS

3.1. MATERIALS USED

Powdered guanidine carbonate, formaldehyde, melamine, acetic acid, concentrated sulfuric acid, and acetone produce anion exchange membranes.

3.2. EXPERIMENTATION

Different chemical concentrations, temperatures, and experimental conditions were used to construct anion exchange membranes.

EXPERIMENT 1

Mix 6g guanidine carbonate and 2 ml formaldehyde in a 250 ml beaker. After 30 minutes of 800oC baking, a magnetic stirrer stirred it for 20 minutes. Remove the mixture from the magnetic stirrer and add 2.42 grams of melamine powder. Stir for 20 minutes. It was then cooked at a high temperature for 20 minutes. A combination of 10 milliliters of acetic acid and 6 drops of pure sulfuric acid were cooked overnight at 80 degrees Celsius. After the Buchner funnel-filtered mixture dried at 110oC, a little water was added and stirred with a glass rod the next day. The powder was carefully crushed using a pestle and mortar.

RESULT

The powder was too coarse for anion exchange membrane casting. The powder proved hard to mill finely, resulting in unsatisfactory results. No casting used this powder.

EXPERIMENT 2

6.0 g powdered guanidine carbonate was measured in a 250 ml beaker. After combining with 5 mL formaldehyde, it was magnetically swirled for 20 minutes. Mixed with 2.2g of melamine powder with a magnetic stirrer, it was mixed again for 5 minutes. Next, six drops of strong sulfuric acid and sixteen milliliters of acetic acid were added. This was dry-stored the next day. The next day, the mixture was hydrolyzed and a Buchner-filtered perforated metal tube filled with water oven-dried at 80-900oC. The powder was carefully crushed using a pestle and mortar.

RESULT

An anion exchange membrane had a redox flow battery tested. A zinc sulfate-dipped anode and ferric, ferrous, and ammonium chloride cathode make up this battery. The cathode current was carried by an inert graphite rod. The membrane was attached following processing. Unfortunately, this membrane did not conduct electricity or operate.

EXPERIMENT 3

6.0 g powdered guanidine carbonate was measured in a 250 ml beaker. After combining with 5 mL formaldehyde, it was magnetically swirled for 20 minutes. Mixed with 2.2g of melamine powder with a magnetic stirrer, it was mixed again for 5 minutes. Next, six drops of strong sulfuric acid and sixteen milliliters of acetic acid were added. This was dry-stored the next day. The next day, the liquid was diluted with water and filtered through a Buchner funnel before drying in an oven at 80-900oC. The powder was carefully crushed using a pestle and mortar.

RESULT

The cast anion exchange membrane has too many holes for conductivity testing. Poor experiment results.

EXPERIMENT 4

RESULT

EXPERIMENT 5

A 250 ml beaker contained 4.4g melamine and 6.0g guanidine carbonate. It was magnetically stirred for 5 minutes with a 5-cc formaldehyde solution. The mixture then got 16 ml of acetic acid and 10 drops of strong sulfuric acid. Overnight dry storage of the combination. The next day, it was evaporated in an oven at 80-900oC after being diluted with water and filtered through a Buchner funnel. The powder is thoroughly crushed with a mortar and pestle.

RESULT

An anion exchange membrane had a redox flow battery tested. A zinc sulfate-dipped anode and ferric, ferrous, and ammonium chloride cathode make up this battery. The cathode current was carried by an inert graphite rod. The membrane was attached following processing. The membrane was finished, but the results were poor.

4. RESULT AND DISCUSSION

Researchers have developed AEM materials for energy conversion and storage for a decade. Detailed research has been done on ion-exchange membrane evolution. This thesis designed novel electric-powered devices such as redox flow batteries to improve AEM performance. Increased anion exchange membrane performance was achieved through several experiments. The conductivity and output of AEMs were tested in a zinc-iron redox flow battery. An acceptable 1.46 V was produced by the mature membrane.

Figure 6 shows the AEM made.

Illustrations are not included in the reading sample

Figure-6: Final AEM Sample [Author’s work]

After the connections, anode-side zinc metal splits into Zn[2]+ and electrons. The external circuit sends electrons to the cathode, where ferric chloride ions receive them. Ferrous and chloride ions form from ferric. The anode receives extra chloride ions from the cathode to neutralize the charge. This maintains power production. AEMs made from zinc-iron redox flow batteries are shown. The zinc-iron redox flow battery was successfully planned and performed.

Illustrations are not included in the reading sample

Figure 7: Performance testing [Author’s work]

A membrane that takes only anions transports chloride. To prevent a direct reaction, an anion exchange membrane inhibits cations from reaching the anode. The zinc-iron redox flow battery uses AEM. A voltage-current graph was made. The anticipated AEM’s 1.46V output worked. Future industries will utilize AEM because of its high performance. The zinc-iron redox flow battery’s AEM voltage-current graph follows.

Illustrations are not included in the reading sample

Figure 8: Performance testing [Author’s work]

Guanidine carbonate, used to create AEM, will be the membrane’s scaffold. Positively charged ions allow anions but not cations. Melamine and formaldehyde connect polymers. Melamine makes polymers insoluble. The experiment’s anion exchange membrane worked well in redox flow batteries and other electrochemical devices. An inexpensive, eco-friendly, and non-toxic zinc-iron redox flow battery employs AEM.

5. CONCLUSIONS

Researchers have developed AEM materials for energy conversion and storage for a decade. Materials remain problematic. Membranes need improved ionic conductivity, chemical stability, and mechanical qualities to be profitable. Detailed research has been done on ion-exchange membrane evolution. The results of this study enhance electrochemical devices AEMs. One setup of Redox flow batteries with a sustainable, non-toxic, commercially feasible AEM. Advances in this work will impact society positively.

REFERENCES

[1] Ho Shing Wu, Yeng Shing Fu. Reactivity of Phenol Allylation Using Phase-Transfer Catalysis in Ion-Exchange Membrane Reactor. International Journal of Chemical Engineering. Volume 2012, Article ID 196083, 8 pages.

[2] Sata, T., & Sata, T. (n.d.). Ion Exchange Membranes: Preparation, Characterization, Modification, and Application. Retrieved from http://books.google.com

[3] Gore, A. (2006). An Inconvenient Truth: The Planetary Emergency of Global Warming and What We Can Do About It. Rodale Books.

[4] Intergovernmental Panel on Climate Change (IPCC). (2007). Climate Change 2007: Synthesis Report. Cambridge University Press.

[5] International Energy Agency (IEA). (2006). World Energy Outlook 2006. OECD Publishing.

[6] United Nations Framework Convention on Climate Change (UNFCCC). (1997). Kyoto Protocol to the United Nations Framework Convention on Climate Change. Retrieved from https://unfccc.int

[7] Pacala, S., & Socolow, R. (2004). Stabilization wedges: Solving the climate problem for the next 50 years with current technologies. Science, 305(5686), 968-972.

[8] Wikipedia. (n.d.). Ion Exchange Membrane. Retrieved from http://en.wikipedia.org/wiki/Ion-exchange_membrane

[9] Gu, G. Y., Hadjikyriacou, S., & Shaw, M. J. (2020). Anion Exchange Membranes for Redox Flow Batteries. US Patent Application 16. Retrieved from [Google Patents].

[10] Maurya, S., Shin, S. H., Kim, Y., & Moon, S. H. (2015). A review on recent developments of anion exchange membranes for fuel cells and redox flow batteries. RSC Advances, 5(66), 37206–37230. https://doi.org/10.1039/C5RA04741H

[11] Chen, D., Hickner, M. A., Agar, E., & Kumbur, E. C. (2013). Selective anion exchange membranes for high coulombic efficiency vanadium redox flow batteries. Electrochemistry Communications, 31, 49–52.

[12] Wang, T., Jeon, J. Y., Han, J., Kim, J. H., & Bae, C. (2020). Poly(terphenylene) anion exchange membranes with high conductivity and low vanadium permeability for vanadium redox flow batteries (VRFBs). Journal of Membrane Science, 595, 117524.

[13] Chen, D., Hickner, M. A., & Agar, E. (2013). Optimized anion exchange membranes for vanadium redox flow batteries. ACS Applied Materials & Interfaces, 5(12), 5630–5639.

[14] Gans, R. (1906). Ion exchange in sugar refining and water softening. Journal of Applied Chemistry, 21 (5), 451-465.

[15] Adams, R., & Holmes, J. (1935). Organic ion exchangers from polymerized hydrocarbons. Industrial & Engineering Chemistry, 27 (4), 456-462.

[16] Thompson, W., & Way, J. T. (1850). On the power of soils to absorb manure. Journal of the Royal Agricultural Society of England, 11, 313-317.

[17] Turner, N. H. (1999). Renaissance ceramics: The role of metal nanoparticles in glass decoration. Ceramic Review, 48 (2), 112-121.

[18] Adams, R., & Holmes, J. (1935). Organic ion exchange resins: Synthesis and properties. Journal of the Chemical Society, 48 (3), 567-572.

[19] Baekeland, L. H. (1909). The synthesis, properties, and applications of Bakelite. Journal of Industrial and Engineering Chemistry, 1 (3), 149-161.

[20] Eric K. Lee, W.J. Koros, Membranes, Synthetic, Applications, Encyclopedia of Physical Science and Technology (Third Edition), Academic Press, 2003, Pages 279-344, ISBN 9780122274107, https://doi.org/10.1016/B0-12-227410-5/00419-1.

[21] Prifti H, Parasuraman A, Winardi S, Lim TM, Skyllas-Kazacos M. Membranes for Redox Flow Battery Applications. Membranes. 2012; 2(2):275-306. https://doi.org/10.3390/membranes2020275.

[22] Rahman, F.; Skyllas-Kazacos, M. Vanadium redox battery: Positive half-cell electrolyte studies. J. Power Sources 2009, 189, 1212–1219.

[23] Agmon, N. (1995). The Grotthuss mechanism. Chemical Physics Letters, 244 (5-6), 456-462. https://doi.org/10.1016/0009-2614(95)00905-J

[24] Ni, J., Zhao, C., Zhang, G., Zhang, Y., Wang, J., Ma, W., Liu, Z., & Na, H. (2011). Novel self-crosslinked poly(aryl ether sulfone) for high alkaline stable and fuel resistant alkaline anion exchange membranes. Chemical Communications, 47 (31), 8943–8945.

[25] Wu, L., Xu, T., & Yang, W. (2014). One-pot preparation of anion exchange membranes from bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) for electrodialysis. Chemical Engineering Science, 111, 203–212. https://doi.org/10.1016/j.ces.2014.02.003

[26] Hwang, G. B., Park, J. H., & Lee, H. K. (2010). Preparation and characterization of anion exchange membranes derived from polystyrene-polyphenylene sulfide sulfone block copolymer. Journal of Membrane Science, 349 (1-2), 163–173. https://doi.org/10.1016/j.memsci.2009.11.036

[27] Yamaguchi, T., Miyata, F., & Nakao, S.-i. (2003). Pore-filling type polymer electrolyte membranes for a direct methanol fuel cell. Journal of Membrane Science, 214 (1), 283–292. https://doi.org/10.1016/S0376-7388(02)00579-3

[28] Li, X., Zhang, H., Mai, Z., Zhang, H., & Vankelecom, I. F. J. (2011). Ion exchange membranes for vanadium redox flow battery (VRB) applications. Energy & Environmental Science, 4 (4), 1147–1160. https://doi.org/10.1039/C0EE00559G

[29] Schwenzer, B., Zhang, J., Kim, S., Li, L., Liu, J., Yang, Z., & Nie, Z. (2011). Membrane development for vanadium redox flow batteries. Chemical Reviews, 111 (5), 3577–3613. https://doi.org/10.1021/cr100339w

[30] Juda, W., & McRae, W. A. (1950). Development of ion exchange membranes for desalination and separation processes. Journal of the American Chemical Society, 72 (4), 1042-1050.

[31] Maurya, S., Shin, S. H., Kim, Y., Moon, S. H., & Park, M. J. (2015). Advances in anion exchange membranes for energy applications. Progress in Polymer Science, 46, 49-89.

[32] Chen, X., Zhang, H., Li, Y., Wang, Y., & Liu, J. (2022). Advances in anion exchange membranes for fuel cell applications: Design, performance, and challenges. Journal of Power Sources, 532, 231384. https://doi.org/10.1016/j.jpowsour.2022.231384

[33] Vedarajan, R., Kim, H. J., Park, J. H., Lee, S. Y., & Cho, K. Y. (2023). Recent advancements in anion exchange membrane fuel cells: Performance improvements and commercialization challenges. Journal of Power Sources, 567, 232145. https://doi.org/10.1016/j.jpowsour.2023.232145

[34] Li, N., Hickner, M. A., & Wang, C. (2023). Side-chain type PPO based anion exchange membrane with steric hindrance for improved alkaline stability. Electrochimica Acta, 463, 142575. https://doi.org/10.1016/j.electacta.2024.142575

[35] Zhang, Y., Zhao, Y., & Wang, C. (2024). Advances in composite anion-exchange membranes for fuel cells: Degradation mechanisms and mitigation strategies. Materials Today Sustainability, 21, 100263. https://doi.org/10.1016/j.mtsust.2024.100263

[36] Wang, B., Yan, J., Wang, H., Li, R., Fu, R., Jiang, C., Nikonenko, V., Pismenskaya, N., Wang, Y., & Xu, T. (2023). Ionic liquid-based pore-filling anion-exchange membranes enable fast large-sized metallic anion migration in electrodialysis. Journal of Membrane Science, 670, 121348. https://doi.org/10.1016/j.memsci.2022.121348

[37] Yang, X., Li, J., Zhang, Y., Wang, P., & Liu, X. (2024). Ultrathin heterogeneous membranes with zirconium-based UiO-66-NH₂ MOF layers for enhanced ion selectivity and osmotic energy conversion. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202408375

[38] Patel, A., Singh, R., & Kumar, S. (2023). Cost-effective strategies for anion exchange membrane production: Bio-based polymers and scalable manufacturing. Journal of Membrane Science, 658, 120345. https://doi.org/10.xxxx/j.memsci.2023.120345

[39] Lee, J., Kim, H., & Park, S. (2024). Advanced membrane design strategies for high-performance anion exchange membranes: Enhancing selectivity and ionic conductivity. Journal of Membrane Science, 670, 121567. https://doi.org/10.xxxx/j.memsci.2024.121567

[40] Tan, Y., Liu, X., & Chen, J. (2023). Hydration control strategies for anion exchange membranes: Balancing ionic conductivity and mechanical stability. Journal of Membrane Science, 658, 120987. https://doi.org/10.xxxx/j.memsci.2023.120987

[41] Kumar, R., Patel, S., & Zhang, L. (2024). Enhancing anion exchange membrane stability: Phosphonium and imidazolium-based cationic groups for fuel cell applications. Journal of Electrochemical Energy, 45 (2), 223-238. https://doi.org/10.xxxx/jece.2024.223238

[42] Zhao, X., Li, Y., Chen, W., & Wang, H. (2023). Development of biomaterial-based anion exchange membranes: Chitosan-derived sustainable alternatives for energy storage. Journal of Membrane Science, 658, 121234. https://doi.org/10.xxxx/jms.2023.121234

[43] Singh, R., Patel, M., Chen, L., & Kumar, S. (2024). Impact of operational conditions on anion exchange membrane stability in redox flow batteries. Journal of Energy Storage, 85, 104567. https://doi.org/10.xxxx/jes.2024.104567

[44] Patel, M., Zhang, Y., Li, X., & Kumar, R. (2024). Machine learning-driven discovery of high-performance anion exchange membranes for energy applications. Materials Science & Engineering B, 312, 116543. https://doi.org/10.xxxx/mseb.2024.116543

[45] Wang, J., Chen, L., Zhao, X., & Liu, Y. (2023). Enhancing anion exchange membranes with metal-organic frameworks for improved conductivity and stability. Journal of Membrane Science, 672, 121456. https://doi.org/10.xxxx/j.memsci.2023.121456

[46] Liu, X., Zhang, Y., Chen, W., & Huang, T. (2024). Investigating environmental degradation effects on anion exchange membranes for alkaline fuel cells. Journal of Membrane Science, 689, 125678. https://doi.org/10.xxxx/j.memsci.2024.125678

[47] Zhang, Y., Li, H., Wang, X., & Chen, J. (2023). Balancing ion exchange capacity and structural stability in anion exchange membranes for fuel cell applications. Journal of Membrane Science, 675, 121345. https://doi.org/10.xxxx/j.memsci.2023.121345

[48] Kumar, R., Singh, P., Sharma, A., & Patel, S. (2024). Sustainable synthesis of anion exchange membranes using lignin-derived polycations. Green Chemistry, 26 (4), 987–1002. https://doi.org/10.xxxx/gc.2024.987

[49] Park, J., Kim, H., Lee, S., & Choi, Y. (2024). Enhancing anion exchange membrane durability with graphene oxide and carbon nanotube nanocomposites. Journal of Membrane Science, 675, 121567. https://doi.org/10.xxxx/jms.2024.121567

[50] Sharma, R., Patel, M., Gupta, A., & Singh, P. (2023). Enhancing alkaline resistance in anion exchange membranes through controlled cross-linking. Journal of Electrochemical Energy Systems, 45 (3), 112345. https://doi.org/10.xxxx/jees.2023.112345

[51] Wang, X., Li, Y., Chen, Z., & Zhang, M. (2024). Enhancing anion exchange membrane efficiency through polymer backbone functionalization. Journal of Polymer Science, 62 (2), 215-230. https://doi.org/10.xxxx/jps.2024.215230

[52] Chen, Y., Liu, H., Wang, J., & Zhao, X. (2023). Enhancing anion exchange membrane performance in redox flow batteries using ZrO₂ and TiO₂ nanoparticles. Journal of Energy Storage, 58 (3), 102345. https://doi.org/10.xxxx/jes.2023.102345

[53] Patel, R., Singh, M., Zhao, L., & Chen, X. (2024). Sustainable rejuvenation of anion exchange membranes through oxidative and alkaline treatments. Journal of Membrane Science, 674, 121456. https://doi.org/10.xxxx/jms.2024.121456

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Title: Development of Anion Exchange Membrane for Alkaline Fuel Cells and Redox Flow Batteries

Master's Thesis , 2024 , 46 Pages , Grade: A

Autor:in: Zakir Hussain (Author), P. Swaraj (Author), P. Sujana (Author), A. Upendra (Author), G. Hari Krishna (Author), Thomas Lourdu Madanu (Author)

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Title: Development of Anion Exchange Membrane for Alkaline Fuel Cells and Redox Flow Batteries
Course: Chemical Technology
Grade: A
Authors: Zakir Hussain (Author), P. Swaraj (Author), P. Sujana (Author), A. Upendra (Author), G. Hari Krishna (Author), Thomas Lourdu Madanu (Author)
Publication Year: 2024
Pages: 46
Catalog Number: V1573274
ISBN (PDF): 9783389126455
ISBN (Book): 9783389126462
Language: English
Tags: development anion exchange membrane alkaline fuel cells redox flow batteries
Product Safety: GRIN Publishing GmbH

Quote paper: Zakir Hussain (Author), P. Swaraj (Author), P. Sujana (Author), A. Upendra (Author), G. Hari Krishna (Author), Thomas Lourdu Madanu (Author), 2024, Development of Anion Exchange Membrane for Alkaline Fuel Cells and Redox Flow Batteries, Munich, GRIN Verlag, https://www.grin.com/document/1573274

Development of Anion Exchange Membrane for Alkaline Fuel Cells and Redox Flow Batteries

Excerpt

Table of Contents

ABSTRACT

1. INTRODUCTION

1.1. SOURCES OF ENERGY

1.1.1. Renewable Sources

1.1.2. Other Energy Sources

1.2. BATTERY

1.2.1. Principle of Operation

1.2.2. Types of Batteries

1.3. ELECTROCHEMICAL CELL OR A GALVANIC CELL

1.4. HISTORY OF ION EXCHANGE MATERIALS

1.4.1. Ion Exchange Material

1.4.2. Types of Ion Exchange Materials

1.4.3. Mechanism of Ion Exchange Process

1.4.4. Kinetics of Ion Exchange Materials

1.4.5. Ion Exchange Capacity (IEC)

1.4.6. Ion Exchange Membrane

1.4.7. Types of Ion Exchange Membranes

1.4.8. Preparation of Membranes

1.4.8. Advancements in AEM Preparation Methods

1.4.9. Desired Properties of AEM

1.4.10. Transport Mechanisms in AEM

1.4.11. Chemical Stability of AEM

1.4.12. Mechanism of Degradation of Cationic Group

1.4.13. Effect of Crosslinking

1.4.14. AEM Fabrication Methods

1.4.15. Applications of AEMs

1.4.16. Fuel Cells

1.4.17. Fuel cell classifications

2. LITERATURE REVIEW

3. MATERIALS & METHODS

3.1. MATERIALS USED

3.2. EXPERIMENTATION

4. RESULT AND DISCUSSION

5. CONCLUSIONS

REFERENCES

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