Anion Exchange Membrane for Redox Flow Battery

Abstract

A flow battery is provided with a thin anion exchange membrane that has low resistance, low diffusivity, a high co-ion transport number, and good chemical stability. At least one rechargeable cell (100) can include an anolyte compartment (120), a catholyte compartment (122), and an anion exchange membrane (110) positioned between the anolyte and catholyte compartments. The anion exchange membrane has a thickness of less than 100 μm and a conductivity of less than 0.4 ppm / hr / cm for cationic species in the rechargeable cell's electrolyte. 2 The anion exchange membrane may have a steady-state diffusion rate of less than 100 . Also disclosed is a method for facilitating use of a flow battery, the method comprising providing an anion exchange membrane. Also disclosed is a method for facilitating charge storage, the method comprising providing a flow battery. Also disclosed is a method for producing an anion exchange membrane.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is directed to "Synthesis of an Anion Exchange Membrane for Redox Flow Battery Applications" 2) Anion Ion Exchange Membrane for a Redox Flow Battery Application” No. 62 / 598,135, filed December 13, 2017, and "Redox Flow Tailoring Anion Ion Exchange Membranes for Low Battery Applications or the Application of Redox Flow Batteries” filed on February 2, 2018. Claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 62 / 625,368. and US Provisional Applications No. 60 / 299,333, filed on Oct. 13, 2003, each of which is incorporated herein by reference in its entirety.

[0002] Aspects and embodiments described herein relate generally to redox flow batteries, and more specifically to The present invention contemplates a negative (anion) ion exchange membrane for use in a redox flow battery. [Background technology]

[0003] Flow batteries are a type of electrochemical cell (battery). In a typical flow battery, the chemical The energy is contained in the corresponding chambers and separated by ion exchange membranes. The flow of current and the corresponding ion exchange can be achieved by two liquid electrolytes separated by a This occurs through the ion exchange membrane as both liquid electrolytes circulate through the chambers. In general, the energy capacity of a flow battery is a function of the amount of liquid electrolyte: Also, the power is a function of the surface area of the electrodes.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The flow battery can operate in two modes. In the first mode, similar to a fuel cell, the used electrolyte is extracted and new electrolyte is added to the system. The used electrolyte can be regenerated by a chemical process for further use. In the second mode, similar to a rechargeable battery, a power source can be connected to the flow battery to regenerate the electrolyte.

Means for Solving the Problems

[0005] A flow battery is provided according to a first aspect. The flow battery can include at least one rechargeable cell. In some embodiments, the flow battery can include a plurality of rechargeable cells within, for example, a housing. The rechargeable cell generally has an anode liquid compartment, a cathode liquid compartment, and an ion exchange membrane positioned between the anode liquid compartment and the cathode liquid compartment. Additional electrolyte can be stored externally, for example, in a tank. This additional electrolyte can be pumped through the anode liquid compartment or the cathode liquid compartment of the rechargeable cell. In some embodiments, the additional electrolyte can be moved via a gravity feed system.

[0006] According to one aspect, a flow battery is provided. The flow battery can include at least one rechargeable cell. The at least one rechargeable cell includes an anode liquid compartment, a cathode liquid compartment, and is positioned between the anode liquid compartment and the cathode liquid compartment. and can have a formed anion exchange membrane. The anode liquid compartment can be configured to hold a first electrolytic solution containing a first cation species . The cathode liquid compartment can be configured to hold a second electrolytic solution containing a second cation species. The anion exchange membrane can be configured to exhibit ion conductivity between the first electrolytic solution and the second electrolytic solution. The anion exchange membrane has a thickness of less than 100 μm, and at least one of the first cation species and the second cation species has a steady-state diffusion rate of less than 0.4 ppm / h / cm . 2 .

[0007] In some embodiments, at least one of the first cation species and the second cation species can be a metal ion. At least one of the first cation species and the second cation species can be selected from zinc, copper, cerium, and vanadium.

[0008] The anion exchange membrane can have a useful life of at least about 12 weeks, determined when the internal potential drop is at least about 2.5 V.

[0009] The anion exchange membrane can have a thickness of less than at least about 55 μm. In some embodiments, the anion exchange membrane can have a thickness between at least about 15 μm and about 35 μm. For example, the anion exchange membrane can have a thickness of about 25 μm.

[0010] In some embodiments, the anion exchange membrane has a steady-state diffusion rate of less than 0.12 ppm / h / cm with respect to at least one of the first cation species and the second cation species. 2A steady diffusion rate of less than can be had.

[0011] After the anion exchange membrane reaches an equilibrium state in a 0.5 M NaCl solution at 25°C when measured with a direct current, it can have a resistance between about 3.0 Ω·cm 2 and about 10.0 Ω·cm 2 The anion exchange membrane can have a resistance between about 5.0 Ω·cm and about 8.0 Ω·cm when measured with a direct current after reaching an equilibrium state in a 0.5 M NaCl solution at 25°C. In some embodiments, the anion exchange 2 membrane can have a co-ion transport rate of at least about 0.95 with respect to at least one non-redox species. 2 The flow battery can coexist with a high voltage direct current (HVDC) power transmission line and can be configured to supply a voltage between about 1000 V and about 800 kV. The flow battery can coexist with a motor vehicle and can be configured to supply a voltage between about 100 V and about 500 V.

[0012] According to another aspect, a method for facilitating the use of a flow battery is provided. The method of the present invention comprises the steps of providing at least one anion exchange membrane and instructing to install each anion exchange membrane within a rechargeable cell of the

[0013] flow battery. The anion exchange membrane has a thickness of less than 100 μm and a steady rate of less than 0.4 ppm / h / cm with respect to at least one of a first metal cation species and a second metal cation species.

[0014] According to another aspect, a method for facilitating the use of a flow battery is provided. The method of the present invention comprises the steps of providing at least one anion exchange membrane and instructing to install each anion exchange membrane within a rechargeable cell of the flow battery. The anion exchange membrane has a thickness of less than 100 μm and a steady rate of less than 0.4 ppm / h / cm with respect to at least one of a first metal cation species and a second metal cation species. The anion exchange membrane has a thickness of less than 100 μm and a steady 2 diffusion rate of less than 0.4 ppm / h / cm with respect to at least one of a first metal cation species and a second metal cation species. It can have a diffusion rate. Each anion exchange membrane can be disposed between the anode liquid compartment and the cathode liquid compartment.

[0015] According to some embodiments, the step of preparing the anion exchange membrane can include preparing an anion exchange membrane having a thickness between about 15 μm and about 35 μm.

[0016] According to some embodiments, the step of preparing the anion exchange membrane has a steady-state diffusion rate of less than 0.12 ppm / hour / cm with respect to at least one of the first metal cation species and the second metal cation species, and the first metal cation species and the second metal cation species are independently selected from zinc, copper, cerium, and vanadium, and can include the step of preparing an anion exchange membrane. / cm 2

[0017] The method of the present invention can further include the step of instructing to charge the flow battery and continuously operate the flow battery.

[0018] According to another aspect, a method for facilitating charge storage is provided. The method of the present invention can include the step of preparing a flow battery and the step of instructing to charge the flow battery. The flow battery can have a plurality of rechargeable cells. Each rechargeable cell can have an anode liquid compartment, a cathode liquid compartment, and an anion exchange membrane positioned between the anode liquid compartment and the cathode liquid compartment. The anode liquid compartment can be configured to hold a first electrolyte having a first cation species. The cathode ​​​​​​​​​​The sword liquid compartment may be configured to hold a second electrolyte having a second cation species. The anion exchange membrane may be configured to exhibit ionic conductivity between the first electrolyte and the second electrolyte. The anion exchange membrane may have a thickness of less than 100 μm and a constant diffusion rate of less than 0.4 ppm / h / cm with respect to at least one of the first cation species and the second cation species. and 2 can have.

[0019] The method of the present invention may further comprise the step of instructing to charge the flow battery by electrically connecting the flow battery to a variable energy source.

[0020] The method of the present invention may further comprise the step of instructing to electrically connect the flow battery to a high voltage direct current (HVDC) power transmission line.

[0021] In some embodiments, the method of the present invention may further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after discharging the flow battery.

[0022] According to another aspect, a method for producing an anion exchange membrane is provided. The method of the present invention includes the steps of integrating a cation-functional monomer having a bridging group into a polymerization product, and coating a microporous substrate having a thickness of less than about 100 μm with the polymerization product. and coating the microporous substrate having a thickness of less than about 100 μm with the polymerization product. In some embodiments, the polymerization product may have substantially no cross-linking agent.

[0023] According to some embodiments, the microporous substrate may have a thickness of about 25 μm. ​​​​​​It is. The microporous substrate can be made of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof, having at least one of them. The microporous substrate can have a porosity between about 25% and 45%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can be made of ultra-high molecular weight polyethylene having a porosity of about 35% and an average pore diameter of about 200 nm. Among them, at least one can be included. The microporous substrate can have a porosity between about 25% and 45%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can have a porosity between about 25% and 45%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can have a porosity between about 25% and 45%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can have a porosity between about 25% and 45%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can be made of ultra-high molecular weight polyethylene having a porosity of about 35% and an average pore diameter of about 200 nm.

[0024] This disclosure contemplates any one or more of the above-described aspects and / or embodiments, and any combination thereof, as well as any one or more of the embodiments described in the detailed description and any examples, and combinations thereof. This disclosure contemplates any one or more of the above-described aspects and / or embodiments, and any combination thereof, as well as any one or more of the embodiments described in the detailed description and any examples, and combinations thereof. This disclosure contemplates any one or more of the above-described aspects and / or embodiments, and any combination thereof, as well as any one or more of the embodiments described in the detailed description and any examples, and combinations thereof.

[0025] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or substantially identical component shown in the various figures is denoted by a similar reference numeral. For clarity, not all components may be labeled with reference numerals in all the drawings. The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or substantially identical component shown in the various figures is denoted by a similar reference numeral. For clarity, not all components may be labeled with reference numerals in all the drawings. The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or substantially identical component shown in the various figures is denoted by a similar reference numeral. For clarity, not all components may be labeled with reference numerals in all the drawings.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0027] Figure 1 is a schematic diagram of an exemplary rechargeable flow cell. This exemplary rechargeable flow cell 100 can have an anode liquid compartment 120 and a cathode liquid compartment 122. The anode liquid compartment 120 and the cathode liquid compartment 122 can be separated by an ion exchange membrane 110 . The arrows indicate the direction of the electrolyte flow through the flow cell 100. The flow cell 100 can further have electrodes 160, 162. In some embodiments , the flow cell 100 can have a bipolar electrode positioned between the adjacent anode liquid compartment 120 and cathode liquid compartment 122 .

[0028] Figure 2 is a schematic diagram of an exemplary flow battery 150 including the rechargeable flow cell 100 . Only one rechargeable flow cell 100 is shown in Figure 2, but generally, it should be understood that a plurality of flow cells 10 0 can be provided in the flow battery 150. The anode liquid compartment 120 and the cathode liquid compartment 122 of the flow cell 100 can be fluidly connected to an external anode liquid tank 130 and a cathode liquid tank 132, respectively. The flow battery 150 can include pumps 140, 142 for circulating the electrolyte. The flow battery 150 can be electrically connected to a charging power source 152 .

[0029] A redox flow battery (RFB) operates by storing energy in two different electrolytes that are often aqueous in practice. The amount of energy stored can depend on the amount of the two electrolytes. The RFB can select the amount of electrolyte to adjust the specific energy amount It can be designed to store. Such technologies can be useful for storing energy from intermittently operating renewable sources. Another possible use in RFBs is in electric vehicles. Their use addresses one drawback of battery-operated vehicles - the time it takes to recharge the battery - by enabling the rapid exchange of spent electrolyte instead of recharging. This solution can be achieved by enabling the rapid exchange of spent electrolyte.

[0030] Typical recharge processes can take several hours to fully charge a battery. In an RFB, the electrolyte can be quickly exchanged from the vehicle. The discharged electrolyte can be removed and replaced with a fully charged electrolyte. Furthermore, since the electrolyte is often in liquid form, it may be possible to "refuel" an RFB vehicle in the same amount of time required to refuel a traditional gasoline-powered vehicle. After removing and replacing the electrolyte, the discharged electrolyte can be recharged or regenerated outside the vehicle for later reuse.

[0031] In any of the RFB applications described above, an ion exchange membrane may be required for the electrochemical cell. It may be required in some RFB applications. The anion exchange membranes described herein are well-suited for RFB applications but are not limited to a particular type or application of RFB technology.

[0032] RFBs apply oxidation-reduction reactions to charge and discharge the cell. RFBs generally operate with redox couples (reductants and oxidants) that function as "locking chelates" in individual electrode compartments during the charge and discharge cycles of the flow battery. The ion exchange membrane is the It can be positioned to separate the anode liquid and the cathode liquid. The ion exchange membrane can be selected to prevent energy release due to the chemical reaction between the oxidizing agent and the reducing agent and ensure that electrical energy is fed to the external load. Exemplary RFBs employ zinc and cerium. Examples of the electrochemical reactions for charging and discharging are given by the following equations, namely, Preventing energy release due to the chemical reaction between the oxidizing agent and the reducing agent, and ensuring that electrical energy is fed to the external load. Exemplary RFBs employ zinc and cerium. are adopted. Examples of the electrochemical reactions for charging and discharging are given by the following equations, namely, Charging Anode reaction: Zn 2+ + 2e ←→ Zn E 0 = -0.763 V Discharging Cathode reaction: 2Ce 4+ + 2e ←→ 2Ce 3+ E 0 = -1.44 V as shown.

[0033] In this exemplary RFB, the total cell potential is 2.203 volts. Such an RFB has an anode liquid containing zinc ions (Zn 2+ 2+) and a cathode liquid containing cerium ions (Ce 4+ 3+). as shown.

[0034] Other examples of the electrochemical reactions for charging and discharging are given by the following equations, namely, Discharging Cathode reaction: Zn 2+ + 2e ←→ Zn E 0 = -0.763 V Charging Anode reaction: Cu 2+ + 2e ←→ Cu E 0 = -0.340 V as shown.

[0035] In this exemplary RFB, the total cell potential is 1.103 volts. Such an RFB has an anode liquid containing zinc ions (Zn2+ ) and a cathode solution having, and copper ions (Cu 2+ ) having It includes an anode solution. FIG. 3 is a schematic diagram of a zinc-copper RFB under charging operation conditions. This exemplary RFB is charged by a DC power source and also includes a Zn cathode solution external tank and a copper Anode solution external tank. These tanks are located on opposite sides of the anion exchange membrane Fluidly connected to the corresponding compartments determined.

[0036] According to some embodiments, the rechargeable cell described herein can include a first and a second electrolyte. Each of the first and second electrolytes can include cations (cations). Cations can generally refer to redox species necessary for electrode reactions in the flow cell. Each electrolyte can include redox species as well as non-redox species. Thus, The anode solution compartment can be configured to hold a first electrolyte having a first cation species, And the cathode solution compartment can be configured to hold a second electrolyte having a second cation species. In some embodiments, at least one of the cation species is a metal ion. For example, at least one of the cation species can be selected from zinc, copper, cerium, and vanadium.

[0037] The cation species can be of the same or different types. In some non-limiting exemplary embodiments, The rechargeable cell can include zinc-cerium, zinc-copper, zinc-zinc, or vanadium -vanadium. When the same anion species is used in the anode solution and the cathode solution, The anion species can have different ionic states. For example, a zinc flow Battery is Zn 0 Or Zn2​+ can include. Vanadium flow batteries can include V 2+ , V 3 + , V 4+ , and / or V 5+ can include. Other anions that can be employed include , bromine, nickel, iron, and cyanide (e.g., ferricyanide).

[0038] The exemplary zinc - cerium RFBs described above generally enable the movement of anions from the anode liquid compartment to the cathode liquid compartment during discharge and also enable the movement of anions from the cathode liquid compartment to the anode liquid compartment during charging and can have an anion exchange membrane. According to some embodiments, the rechargeable cells described herein can have an anion exchange membrane positioned between the anode liquid compartment and the cathode liquid compartment. This anion exchange membrane can be ion - conductive between the electrolytes. Generally, the anion exchange membrane can be ion - conductive between ions not involved in the electrode reaction.

[0039] Anion exchange membranes can generally transport anions under a potential difference. Anion exchange membranes can have fixed positive charges and mobile anions. Ion exchange membrane properties can be controlled by the amount, type, and distribution of fixed ionic groups within the exchange membrane. For example, quaternary and tertiary amine functional groups can give rise to fixed positive charge groups in strong and weak basic anion exchange membranes. Bipolar thin films can sometimes have a cation exchange membrane and an anion exchange membrane laminated or bonded to each other with a thin intervening neutral layer .

[0040] ​A polymer electrolyte membrane (PEM) acts as an electrolyte and a separator between the anolyte and catholyte. Anion PEMs are ion exchange membranes that can act as a separator. Positively charged groups attached to the mer or as part of the polymer, such as sulfonic acid groups and / or amine groups. In use, the proton, i.e., the cation, is generally They penetrate the membrane by transferring one positive charge fixed on the membrane to another charge that permeates the membrane. Can be moved.

[0041] The parameters for membrane selection generally include proper chemical, thermal and electrochemical and mechanical stability. Adequate mechanical stability when inflated and under mechanical stress. The quality and strength of the material can also be considered. Other parameters include low resistance, low or favorable The ion exchange membrane has the potential to provide a transport property of electrolyte species that is not available in conventional ion exchange membranes, and to provide low cost. There may be a balancing of some or all of these properties to overcome competing effects. The exchange membrane can be selected to meet a number of characteristics, including: (1) operation; (2) low electrical resistance to reduce potential drop in the (3) High transference number, including the ability to withstand any pH ranging from 0 to 14 and oxidizing chemicals (4) chemical stability to the stresses encountered during the manufacture of modules or other processing devices; (5) good dimensional stability in operation, e.g., when the contact fluid is concentrated Select one that has the proper resistance to expansion or contraction when changing temperature or humidity. This can be done.

[0042] According to some non-limiting embodiments, the anion exchange membrane for the RFB is anion exchange membrane for multiple cycles. Chemical stability against the battery electrolyte and voltage drop during discharge cycles (including high ampere operation) Select a high conductivity that minimizes, prevents co-ion transport, and has excellent selectivity to maintain high efficiency during the service life of the RFB. It can be selected to have.

[0043] The inventor generally finds that for a given ion exchange membrane, thinner membranes result in lower resistivity and also allow for a larger membrane area per unit volume of the device. However, thinner membranes are generally more susceptible to dimensional changes from environmental effects such as changes in the ion concentration of the contacting fluid or the operating temperature. Generally, it can be more difficult to develop and produce thinner membranes without defects, which is because the error margin during production is smaller compared to thicker thin films that can cover defects that occur during formation.

[0044] Thin anion exchange membranes with low resistance, low diffusivity, high co-ion transport rate, and good chemical stability can be produced by polymerizing cation-functional monomers with cross-linking groups. As described herein, composite ion exchange membranes have been developed, which have microporous thin films saturated with cross-linked polymers having charged ion groups. The anion exchange membranes described herein have a thickness of less than 100 μm and a resistance of 5. 0 Ω·cm ~8.0 Ω·cm and can result in a steady-state diffusivity of less than 0.4 ppm / h / cm with respect to at least one cationic species. The properties of the ion exchange membranes described herein generally allow the membrane to operate at low resistance without sacrificing membrane integrity. 0 Ω·cm 2 ~8.0 Ω·cm 2 and have a resistance of, and with respect to at least one cationic species result in a steady-state diffusivity of less than 0.4 ppm / h / cm. The 2 ion exchange membranes described herein characteristics generally allow the membrane to operate at low resistance without sacrificing membrane integrity. It can be done. The same method can be implemented in the production of cation exchange membranes and is to be understood. That is, in this case, the ionic polymer has relevant functional groups. That is, in this case, the ionic polymer has relevant functional groups.

[0045] WO 2011 / 025867 (incorporated herein by reference in its entirety) describes a method for producing an ion exchange membrane comprising the steps of binding one or more monofunctional ionogenic monomers to at least one multifunctional crosslinking monomer and polymerizing the monomer in the pores of a porous material. WO 2011 / 025867 (incorporated herein by reference in its entirety) describes a method for producing an ion exchange membrane comprising the steps of binding one or more monofunctional ionogenic monomers to at least one multifunctional crosslinking monomer and polymerizing the monomer in the pores of a porous material. WO 2011 / 025867 (incorporated herein by reference in its entirety) describes a method for producing an ion exchange membrane comprising the steps of binding one or more monofunctional ionogenic monomers to at least one multifunctional crosslinking monomer and polymerizing the monomer in the pores of a porous material. WO 2011 / 025867 (incorporated herein by reference in its entirety) describes a method for producing an ion exchange membrane comprising the steps of binding one or more monofunctional ionogenic monomers to at least one multifunctional crosslinking monomer and polymerizing the monomer in the pores of a porous material.

[0046] According to one aspect, a method for producing the ion exchange membrane described herein is provided. The present disclosure generally describes the chemicals and materials used to produce exemplary ion exchange membranes. To produce a crosslinked membrane, the micropores of a substrate can be saturated with a polymerization product consisting of a crosslinking functional monomer, followed by polymerizing the monomer. According to one aspect, a method for producing the ion exchange membrane described herein is provided. The present disclosure generally describes the chemicals and materials used to produce exemplary ion exchange membranes. To produce a crosslinked membrane, the micropores of a substrate can be saturated with a polymerization product consisting of a crosslinking functional monomer, followed by polymerizing the monomer. According to one aspect, a method for producing the ion exchange membrane described herein is provided. The present disclosure generally describes the chemicals and materials used to produce exemplary ion exchange membranes. To produce a crosslinked membrane, the micropores of a substrate can be saturated with a polymerization product consisting of a crosslinking functional monomer, followed by polymerizing the monomer. According to one aspect, a method for producing the ion exchange membrane described herein is provided. The present disclosure generally describes the chemicals and materials used to produce exemplary ion exchange membranes. To produce a crosslinked membrane, the micropores of a substrate can be saturated with a polymerization product consisting of a crosslinking functional monomer, followed by polymerizing the monomer.

[0047] The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure. The monomer can have a functional group and a crosslinking group. Here, the term "crosslinking group" can refer to a portion having a monomer substituent or a polymerization reaction site that can form a networked or crosslinked polymer. The term "ionic functional group" can refer to a portion having a monomer substituent or a covalently bonded charged group. The charged group can be positively or negatively charged. The monomers described herein can generally have at least one functional group and at least one crosslinking group. According to some embodiments, the molecules described herein can have a hydrocarbon-based structure.

[0048] The functional crosslinking monomer can provide stability to the membrane. The membrane stability and relative compactness generally depend on the degree of crosslinking of the same monomer. The stability can further depend on the miscibility between the functional group and the crosslinking group. When the two groups are not miscible, typically due to the hydrophobicity and hydrophilicity of the crosslinking group and the ionic group respectively, a solvent can be added to produce a polymerized solution. During the thermal polymerization process, the volatile solvent can evaporate and change the monomer distribution in the solution. The solvent can further change the reactivity of the two groups due to the solvent-solubilizing effect. This result generally forms a block copolymer instead of producing a uniform monomer distribution.

[0049] If the functional monomer itself is not crosslinked, the functional group may be at risk of detaching from the polymer network. When each functional group crosslinks, only the hydrolysis of the ester group reduces the degree of crosslinking, which can reduce the degradation rate of the membrane. Therefore, when obtained with the functional crosslinking monomer described herein, the monomer can be in a sufficiently crosslinked state, and the functional group can covalently bond to the polymer backbone of the membrane. When the degradation rate of the membrane decreases, as a result, the chemical stability in the electrolyte solution can be increased and the lifespan can be significantly increased. In addition, due to the crosslinking group, the polymerization product can

[0050] In some non-limiting embodiments, the method of the present invention includes integrating a cationic functional monomer having a crosslinking group into the polymerization product, and micropores having a thickness of less It can have a step of coating a substrate with a polymerization product. The polymerization product can contain a solvent. The polymerization product can contain a polymerization initiator.

[0051] As the functional group, there can be a positively charged amine group, for example, a quaternary ammonium group. The tertiary ammonium group can be quaternized with a quaternizing chemical substance. The quaternary ammonium functional group has basicity in strength and can be ionized to enable a wide range of operating ranges acting over a pH range of 0 to 14.

[0052] The crosslinking group can produce a film with a high crosslinking density without adding an external crosslinking agent. The crosslinking monomer can have at least one polymerization reaction site. In some embodiments the crosslinking monomer can have more than one polymerization reaction site. In some embodiments, the polymer is 100% crosslinked.

[0053] The cationic functional monomer can be copolymerized with at least one secondary functional monomer. The secondary functional monomer can be configured or selected to change the ion exchange capacity without crosslinking. The secondary functional monomer can be selected from, but not limited to, vinylbenzyltrimethylammonium chloride, trimethylammonium chloride·ethyl methacrylate, methacrylamidepropyltrimethylammonium chloride, (3 - acrylamidopropyl)trimethylammonium chloride, 4 - vinylpyridine, and a group containing one or more polymerization initiators. from which to select.

[0054] The cationic functional monomer can be copolymerized with at least one non - functional secondary monomer. The non-functional secondary monomer can be configured or selected to modify the resistivity of the film. The non-functional secondary monomers can modify the miscibility of the monomers and / or the polymerization product. For example, the non-functional monomer may be configured or selected to have a crosslinking group and an isopropyl group. The carboxylate groups are selected for their ability to prevent phase separation caused by the hydrophobic and hydrophilic properties of the carboxylate groups, respectively. Furthermore, copolymerization with non-functional monomers can be carried out without excess solvent. In some embodiments, the composition may be kept thoroughly mixed. Non-functional secondary monomers include, but are not limited to, styrene, vinyl toluene, 4-methyl styrene. , t-butylstyrene, α-methylstyrene, methacrylic anhydride, methacrylic acid, n-vinyl Vinyl-2-pyrrolidone, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl-tris -(2-Methoxyethoxy)silane, vinylidene chloride, vinylidene fluoride, vinylmethyldimethyl Toxosilane, 2,2,2-trifluoroethyl methacrylate, allylamine, vinyl piperidine Lysine, Maleic Anhydride, Glycidyl Methacrylate, Hydroxyethyl Methacrylate, or ethyl methacrylate.

[0055] In some embodiments, and for some contemplated uses, a crosslinker may be incorporated. Such crosslinking agents include, for example, propylene glycol dimethacrylate, Isobutylene glycol dimethacrylate, Octa-vinyl POSS®, Kuta-vinyl dimethylsilyl POSS(registered trademark), Vinyl POSS(registered trademark) Mixture Octa Vinyl POSS®, Trisilabol Ethyl POSS®, Risilanolisooctyl POSS (registered trademark), octasilane POSS (registered trademark), octa hydro POSS (registered trademark), epoxycyclohexyl-POSS (registered trademark) cage mi xtures, glycidyl-POSS (registered trademark) cage mixtures, methacryl-POSS( registered trademark) cage mixtures, or acrylo POSS (registered trademark) cage mixtures can be selected, and all of these are distributed by Hybrid Plastics, Inc. (Hattiesburg, Mississippi, USA).

[0056] The method of the present invention comprises the step of coating a microporous substrate with a polymerization product. This polymerization product can contain one or more solvents. Solvents that can be incorporated include 1-propanol and dipropylene glycol. In some embodiments hydroxyl groups can be incorporated, such as solvents like alcohols (e.g., isopropanol, butanol, diols such as various glycols, or polyols such as glycerin). Additionally, aprotic solvents such as N-methylpyrrolidone and dimethylacetamide can be incorporated. These solvents are exemplary, and additional or alternative solvents will be apparent to those skilled in the art.

[0057] The polymerization product is a free radical initiator, for example, benzoyl peroxide (BPO), ammonium persulfate um, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2-methylpro pionamidine) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2yl)propane dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2yl)propane], and dimethyl ​​​​It may contain 2,2'-azobis(2-methylpropionate).

[0058] The microporous substrate can be selected to have appropriate mechanical stability, porosity, and thickness. According to some embodiments, the microporous substrate has a thickness of less than 100 μm, a void (porous) ratio between about 25% and 4 5%, and an average pore diameter between about 50 nm and about 10 μm. The microporous substrate can be made of polypropylene, high molecular weight polyethylene, ultra-high high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and at least one of their combinations. These exemplary materials can generally have high mechanical stability at a thickness of 15 μm or more.

[0059] Generally, the thickness of the microporous substrate can be as thin as possible while providing appropriate mechanical stability for the anion exchange membrane. The thickness of the microporous substrate can be measured without considering the depth of the pores. In some embodiments, the microporous substrate can have a thickness of less than about 15 5 μm. The microporous substrate can have a thickness of less than about 100 μm. The microporous substrate can have a thickness of less than about 75 μm. The microporous substrate can have a thickness of less than about 55 μm. According to some embodiments, the microporous substrate can have a thickness of about 25 μm. The microporous substrate can have a thickness of about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, or about 45 μm.

[0060] The porosity can maintain appropriate mechanical stability and provide an appropriate coating for the substrate. It can be selected to enable. Therefore, the porosity can be selected based on the coating composition, the substrate material, and / or the substrate thickness. The porosity expressed as a percentage can refer to the amount of pores relative to the total volume of the substrate. In some embodiments, the microporous membrane can have a porosity between about 25% and about 45%. The microporous membrane can have a porosity between 20% and 40%. The microporous membrane can have a porosity of about 20%, about 25%, about 30%, about 35%, about 40%, or about 45%. In other embodiments, the porosity can be greater than about 45%. For example, the porosity can be greater than about 60%, or greater than 70%. In a non-limiting exemplary embodiment, the substrate material can be ultra-high molecular weight polyethylene, and the thickness of the substrate can be between about 15 μm and 35 μm, and the porosity can be selected to be about 35%.

[0061] The porosity can further be selected to correspond to the selected average pore size, and vice versa. The average pore size can further be selected based on the coating composition and / or the substrate material. For example, the average pore size can be selected such that the coating on the substrate can be made substantially uniform. The average pore size can alternatively or additionally be selected to have an effect on the membrane performance. The pore size of the membrane can change the resistivity, diffusivity, ion transport rate, and tightness of the membrane structure. Without wishing to be bound by any particular theory, the selected membrane parameters (especially pore size, degree of crosslinking, ionic functionality, and thickness) together enable the membrane performance.

[0062] In some embodiments, the average pore diameter can range from about 50 nm to about 10 μm. It can range from about 100 nm to about 1.0 μm. It can range from about 100 nm to about 200 nm. The average pore diameter can be about 100 nm, about 125 nm, about 150 nm, about 175 nm, about 200 nm, about 225 nm, or about 250 nm.

[0063] The microporous substrate material can be selected to have appropriate mechanical stability at a desired thickness and porosity. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability. In some embodiments, the microporous substrate can have at least one of polypropylene, high molecular weight polyethylene, ultra-high molecular weight polyethylene, polyvinyl chloride, polyvinylidene fluoride, polysulfone, and combinations thereof. These exemplary materials generally can have high mechanical stability at a thickness of 15 μm or more. Additionally, the exemplary materials can have a porosity reaching up to 70% at such a thickness and still have mechanical stability.

[0064] The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating. The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating. The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating. The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating. The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating. The method of the present invention can further comprise a step of heating the coated microporous substrate or performing the coating step at an elevated temperature. For example, making the substrate pore filling or saturation state can be carried out at a temperature higher than about 40 °C or at about 40 °C to reduce the air solubility. In some embodiments, the substrate can be coated by immersing it in a polymerization solution under vacuum treatment, and a heating step is performed after this coating.

[0065] The method of the present invention comprises a step of removing air bubbles after coating a microporous substrate. In some embodiments, the substrate sample is pre-soaked and treated to remove air bubbles, for example , this can be done by placing the sample on a polyester or similar sheet, covering it with a cover sheet , and smoothing it to remove air bubbles. This process can be carried out within a single sheet or a sheet assembly.

[0066] Polymerization can be carried out in a heating unit or on a heating surface. The coated substrate is placed on the heating surface for a temperature and time sufficient to initiate and complete the polymerization . The sufficient time and temperature can generally depend on the polymerization product composition. The polymerization reaction can employ, for example, treatment with ultraviolet light or ionizing radiation (such as gamma radiation or electron beam radiation) . .

[0067] According to some embodiments, the method described herein can significantly reduce production time, for example, by requiring only one coating step . The production time can be further shortened by not incorporating a cross-linking agent additionally. The subsequent cross-linking step can be avoided. Furthermore, the produced anion exchange membrane has a thickness of about 25 μm or 15 μm and can maintain the desired mechanical strength and chemical stability during use .

[0068] The membrane can be produced on a production line as shown in FIG. 4. The exemplary production line 200 in FIG. 4 has a solution tank 210 for coating the membrane substrate. This exemplary production . Production line 200 can coat along the heating zone 220 on the mechanical moving element 230 and move the substrate that is placed thereon. The mechanical moving element can optionally be a conveyor belt 230 having a motor 232. This motor can operate to control the speed along the heating zone 220 (as will be described in more detail in the examples). The heating zone 220 can include a plurality of heating blocks 221, block 222, block 223, block 22 4. Here, the exemplary heating zone 220 has four heating blocks (heating areas), but the heating zone 220 can have more or fewer heating blocks. The number of heating blocks can affect the operating speed of the mechanical moving element 230. Production line 200 can further have a roller 240 for removing bubbles. In other embodiments, the heating zone 220 can be a light initiator instead of a thermal initiator (starting device ). In some embodiments, the heating zone 220 can have an ultraviolet radiation zone. Generally, the thickness of the ion exchange membrane can enable a lower internal resistance and / or a higher power output. The thickness of the anion exchange membrane can depend on the thickness of the microporous substrate. Therefore, the anion exchange membrane can have a thickness of less than about 155 μm.

[0069] The anion exchange membrane can have a thickness of less than about 100 μm. The anion exchange membrane can have a thickness of less than about 75 μm. The anion exchange membrane can have a thickness of less than about 55 μm. The anion exchange membrane can have a thickness of about 15 μm, about 20 μm, about 25 μm, about 30 μm, about 35 μm, about 40 μm, about 45 μm.

[0070] In some embodiments, the anion exchange membrane can have a thickness between about 15 μm and about 100 μm. The anion exchange membrane can have a thickness between about 15 μm and about 75 μm. The anion exchange membrane can have a thickness between about 15 μm and about 50 μm. The anion exchange membrane can have a thickness between about 15 μm and about 35 μm. The anion exchange membrane can have a thickness between about 15 μm and about 25 μm. can.

[0071] The ion exchange membranes described herein exhibit excellent diffusivity compared to conventional membranes of similar thickness. Generally, diffusivity can mean the number of ions crossing a unit area of the ion exchange membrane over a given time. Thus, the diffusivity of the membrane can be driven by the concentration difference of the species across the membrane. Steady-state diffusivity can mean a diffusivity where the flux of ions is approximately constant over time. As described herein, the steady-state diffusivity is measured for at least one cationic species. Furthermore, the value of the steady-state diffusivity is determined by measuring the membrane sample between a 0.4 M CuSO4 solution and a 0.5 M NaCl solution at 25 °C and monitoring the Cu in the compartment of the 0.5 M NaCl solution. 2+ can be.

[0072] In some embodiments, the anion exchange membrane can have a steady-state diffusivity of less than 0.4 ppm / h / cm for at least one cationic species. 0.4 ppm / h / cm 2 for some embodiments In some embodiments, the anion exchange membrane has a steady-state diffusivity of less than 0.4 ppm / h / cm for both cationic species. 2 less than ​It can have a steady diffusion rate. The anion exchange membrane is 0.3 ppm / h / cm 2 less than, 0.2 ppm / h / cm 2 less than, 0.15 ppm / h / cm 2 less than, 0.12 ppm / h / cm 2 less than, 0.1 ppm / h / cm 2 less than, 0.08 ppm / h / cm 2 less than, 0.05 ppm / h / cm 2 less than, 0.03 ppm / h / cm 2 It can have a steady diffusion rate less than. Thus, the values of the steady diffusion rate described above are accurate when testing the membrane between a 0.4 M CuSO4 solution and a 0.5 M NaCl solution at 25°C, and also monitoring Cu in the compartment of the 0.5 M NaCl solution. 2+

[0073] A lower electrical resistance of the membrane can reduce the electrical energy required for operation. The membrane specific resistance is generally reported in ohm·length (Ωcm). However, the resistance may not be uniformly distributed along the membrane area. The area membrane resistance is measured in ohm·area (Ωcm 2 ). The area membrane resistance can be measured by comparing the electrolyte resistance of a flow cell having an ion exchange membrane with that of a flow cell without an ion exchange membrane. For example, a cell having two electrodes (generally platinum or graphite can be used) of a known area in an electrolyte solution can be set up. One cell can have an ion exchange membrane sample of a known area between the electrodes. The electrodes are positioned so as not to contact the membrane. The membrane resistance can be estimated by subtracting the electrolyte resistance without the membrane from the electrolyte resistance having the membrane at a predetermined position. ​​​​​​

[0074] The ion exchange membrane resistance can also be measured by determining the voltage-current curve in a cell having two well-stirred chambers separated by the membrane. The mercury(I) chloride electrodes can be positioned to measure the potential drop across the membrane. The gradient of the potential drop can be plotted against the current curve, which is obtained by varying the voltage and measuring the current. The mercury(I) chloride electrodes can be positioned to measure the potential drop across the membrane. The potential drop gradient can be plotted against the current curve, which is obtained by varying the voltage and measuring the current. drop gradient can be plotted against the current curve, which is obtained by varying the voltage and measuring the current.

[0075] Furthermore, the ion exchange membrane resistance can be measured using electrochemical impedance. An alternating current can be applied to the membrane in this method. Generally, measurements at a single frequency provide data related to the electrochemical properties of the membrane. By using variations in frequency and amplitude, detailed structural information can be obtained. Furthermore, the ion exchange membrane resistance can be measured using electrochemical impedance. An alternating current can be applied to the membrane in this method. Generally, measurements at a single frequency provide data related to the electrochemical properties of the membrane. By using variations in frequency and amplitude, detailed structural information can be obtained. Furthermore, the ion exchange membrane resistance can be measured using electrochemical impedance. An alternating current can be applied to the membrane in this method. Generally, measurements at a single frequency provide data related to the electrochemical properties of the membrane. By using variations in frequency and amplitude, detailed structural information can be obtained. Furthermore, the ion exchange membrane resistance can be measured using electrochemical impedance. An alternating current can be applied to the membrane in this method. Generally, measurements at a single frequency provide data related to the electrochemical properties of the membrane. By using variations in frequency and amplitude, detailed structural information can be obtained.

[0076] In some embodiments, the anion exchange membrane can have a resistance between about 3.0 Ω·cm and about 10.0 Ω· 2 ~ about 10.0 Ω· cm when measured with a direct current after equilibration in a 0.5 M NaCl solution at 25°C. The anion exchange membrane can have a resistance between about 5.0 Ω·cm 2 and about 8.0 Ω· cm when measured with a direct current after equilibration in a 0.5 M NaCl solution at 25°C. The anion exchange membrane can have a resistance between about 5.0 Ω·cm 2 and about 8.0 Ω·cm 2 when measured with a direct current after equilibration in a 0.5 M NaCl solution at 25°C. The anion exchange membrane can have a resistance between about 6.0 Ω·cm and about 7.0 Ω·cm when measured with a direct current after equilibration in a 0.5 M NaCl solution at 25°C. The resistance is 2 ~ about 7.0 Ω·cm 2 when measured with a direct current after equilibration in a 0.5 M NaCl solution at 25°C. The resistance is , as low as possible depending on other parameters of the film (e.g., material, thickness, etc.). In some embodiments, the present disclosure may be modified or determined. As described in the document, ion exchange membranes produced with almost no cross-linking agent are different from ion exchange membranes produced with cross-linking agent. The anion exchange membrane has a lower resistance than the anion exchange membrane. When measured with a direct current after equilibrating in a 0.5M NaCl solution, the resistance is approximately 3.0 Ω cm 2 , about 4.0Ω cm 2 , approximately 5.0Ω cm 2 , about 5.5Ω cm 2 , about 6.0Ω cm 2 , Approximately 6.5Ω cm 2 , about 7.0Ω cm 2 , about 7.5Ω cm 2 , about 8.0Ω cm 2 , about 9 .0 Ω cm 2 , about 10.0Ω cm 2 The resistance of the resistor may be 0.01 to 0.05.

[0077] The co-ion transport number is generally defined as the ratio of the number of counter ions to the number of co-ions during use in a flow battery. Relative transport. An ideal cation exchange membrane would allow only positively charged ions to pass through the membrane. This can result in a co-ion transport number of 1.0. This is determined by measuring the potential across the membrane in the presence of a solution of a monovalent salt of a given concentration. The methods and calculations used herein are explained in more detail in the Examples section.

[0078] In some embodiments, the anion exchange membrane is ion exchangeable to at least one non-redox species. As a non-redox species, it can have a co-ion transport number of at least about 0.95. There can be any non-redox species of electrolyte. The anion exchange membrane can have a co-ion transport rate of at least about 0.95 for all non-redox species. The anion exchange membrane can have a co-ion transport rate of at least about 0.9, at least about 0.91, at least about 0.92, at least about 0.93, at least about 0.94, at least about 0.95, at least about 0.96, at least about 0.97, at least about 0.98, at least about 0.99.

[0079] The flow cell can further include at least one electrode. The power of the flow cell can be a function of the surface area of the electrode. One electrode can be a bipolar electrode positioned to be in fluid communication with the first electrolyte solution and the second electrolyte solution. The bipolar electrode can be positioned between the first electrolyte solution and the second electrolyte solution. The electrodes described herein can be composed of a corrosion-resistant conductive material selected to have suitable electrical, chemical, and mechanical stability for use. The bipolar electrode can be one having a conductive material or a layer of a conductive material. In some embodiments, the bipolar electrode can be one having zinc.

[0080] The flow cell can have a first electrode and a second electrode, with one of each positioned within each cell half. The first electrode can be positioned within the cell half containing the first electrolyte solution, and the second electrode can be positioned within the cell half containing the second electrolyte solution. The electrodes can have a conductive material or one or more layers of a conductive material. In some embodiments, the electrodes can have platinum or graphite. The flow cell includes an ion exchange membrane and electrodes. ​​​​​​​​​​​​having at least one separator configured to maintain without contacting each other can do.

[0081] A flow battery includes a plurality of flow cells. In some embodiments, the flow battery can include an external electrolyte tank. The flow battery can be configured to feed the electrolyte from the tank and pass it through the cell to contact the ion exchange membrane and / or the electrodes. The flow battery can include one or more pumps configured to circulate the electrolyte through the cell. The flow cells can be fluidly connected to each other. In some embodiments, the flow cells are not fluidly connected to each other. The flow battery can include one or more pumps configured to circulate the electrolyte through the cell. The flow cells can be fluidly connected to each other. In some embodiments, the flow cells are not fluidly connected to each other. The flow cells can be fluidly connected to each other. In some embodiments, the flow cells are not fluidly connected to each other. In some embodiments, the flow cells are not fluidly connected to each other.

[0082] According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery. According to other aspects, a method for facilitating the use of a flow battery is provided. The method of the present invention can include providing at least one ion exchange membrane as described in the specification and instructing to install the ion exchange membrane in a rechargeable cell of the flow battery. The ion exchange membrane can be an anion exchange membrane. Generally, the ion exchange membrane can be installed between the anode liquid compartment and the cathode liquid compartment of the rechargeable cell. The method of the present invention can further include instructing to charge the flow battery and continuously operate the flow battery.

[0083] In some embodiments, the flow battery can operate with a lifespan of at least about 6 weeks until the electrolyte needs to be exchanged or recharged. The flow battery can operate with a lifespan of at least about 12 weeks. In some embodiments, the ion exchange membrane has a useful lifespan of about 6 weeks, about 8 weeks, about 10 weeks, about 12 weeks, about 14 weeks, or about 16 weeks. In some embodiments, the flow battery can operate with a lifespan of at least about 6 weeks until the electrolyte needs to be exchanged or recharged. The flow battery can operate with a lifespan of at least about 12 weeks. In some embodiments, the ion exchange membrane has a useful lifespan of about 6 weeks, about 8 weeks, about 10 weeks, about 12 weeks, about 14 weeks, or about 16 weeks. In some embodiments, the flow battery can operate with a lifespan of at least about 6 weeks until the electrolyte needs to be exchanged or recharged. The flow battery can operate with a lifespan of at least about 12 weeks. In some embodiments, the ion exchange membrane has a useful lifespan of about 6 weeks, about 8 weeks, about 10 weeks, about 12 weeks, about 14 weeks, or about 16 weeks. In some embodiments, the ion exchange membrane has a useful lifespan of about 6 weeks, about 8 weeks, about 10 weeks, about 12 weeks, about 14 weeks, or about 16 weeks. It can be. In some embodiments, the ion exchange membrane can have a useful life reaching up to about 20 weeks. The useful life of the membrane can be described as the number of cycles the membrane can operate before the electrolyte needs to be replaced. In some embodiments, the ion exchange membrane can operate for more than 4000 cycles. For example, the ion exchange membrane can operate for about 4500 cycles, about 5000 cycles, about 5500 cycles, about 6000 cycles, about 6500 cycles, or about 7000 cycles. As described herein, the useful life can mean the life of the flow battery or ion exchange membrane in continuous use before the electrolyte needs to be replaced or recharged.

[0084] In non - limiting exemplary embodiments, when Cu2+ diffuses into the Zn2+ compartment (or conversely Zn2+ diffuses into the Cu2+ compartment), Cu2+ can react with the Zn metal formed during discharge. This reaction can convert Cu2+ to Cu, reducing the conductivity at a constant current or increasing the voltage. The voltage can be a good indicator of the amount of Cu2+ diffusing through the membrane. + diffuses into the Zn2+ compartment (or conversely Zn2+ + diffuses into the Cu2+ compartment), Cu2+ can react with the Zn metal formed during discharge. + to Cu2+ 2 + compartment, Cu2+ + can react with the Zn metal formed during discharge. This reaction can convert Cu2+ + to Cu 0 and reduce the conductivity at a constant current or increase the voltage. The voltage can be a good indicator of the amount of Cu2+ diffusing through the membrane. + indicator. Thus, the useful life of the ion exchange membrane can reach the threshold when the internal potential drop is high and the output is low, indicating that the electrolyte needs to be replaced or recharged. In some embodiments, the useful life threshold of the ion exchange membrane may be reached when the internal potential drop is between about 2.0 volts and about 3.0 volts. The internal potential drop may be low. When there is, it may reach the useful life threshold of the ion exchange membrane. It may reach the useful life of the ion exchange membrane threshold when at least about 2.5 volts. The flow batteries described herein may include a sensor that determines an internal potential drop, and optionally a user interface that indicates when the internal potential drop has reached a useful life threshold.

[0085] The useful life of the ion exchange membrane may depend on the usage of the membrane. For example, the useful life may vary depending on the selection of the electrolyte or the electrode material. The useful life of the ion exchange membrane may vary depending on the size of the rechargeable cell, the electrode and / or the electrolyte compartment. The useful life of the ion exchange membrane may further vary depending on the material selected. For example, the useful life may vary depending on the coating material, the substrate material and whether the substrate is coated with a crosslinking agent. Generally, the ion exchange membrane can have a useful life of about 6 weeks to about 16 weeks. The method of the present invention may further include the step of indicating to determine the useful life of the ion exchange membrane, and also optionally the step of indicating to replace the electrolyte after depletion of the electrolyte. In some embodiments, the method of the present invention may include the step of replacing the ion exchange membrane after depletion of the ion exchange membrane.

[0086] According to some embodiments, the flow battery can be configured to be compatible with a high voltage direct current (HVDC) power transmission line. The flow battery can operate to store electrical energy for use on an HVDC power transmission line. Generally, such a flow battery can supply a voltage between about 1000V and about 800KV.

[0087] According to some embodiments, the flow battery can be configured to coexist with a motor vehicle. The flow battery can be operated to store electrical energy for use in a motor vehicle. Such a flow battery can supply a voltage between about 100 V and about 500 V to accommodate a conventional motor vehicle battery.

[0088] In another aspect, the present invention provides a method for facilitating the storage of charge. The method comprises the steps of providing a flow battery as described herein and instructing the flow battery to be charged. The flow battery can be charged by connecting it to an energy source. In some embodiments, the flow battery can be charged by connecting it to a variable energy source. The variable energy source can be any energy source that is non - transportable due to its variable nature. Examples of variable energy sources can include photovoltaic systems, wind power systems, and hydroelectric power systems such as wave power and tidal power. Other variable energy sources will be readily apparent to those skilled in the art. Generally, the variable energy source can include sources that require high - energy storage to provide continuous operation. Thus, the method of the present invention can further comprise the step of instructing the flow battery to be charged by electrically connecting the flow battery to an energy source, for example, a variable energy source. The method of the present invention can further comprise the step of instructing the flow battery to be electrically connected to an energy transmission line or to a point of use, for example, directly to a customer.

[0089] The flow battery can be electrically connected to an HVDC power transmission line. The HVDC power transmission line is long ​ It can be used for power transmission over long distances. The HVDC power transmission line can further be electrically connected to a regional power distribution system, for example, an alternating current (AC) regional power distribution system. It can be used for power transmission over long distances. The HVDC power transmission line can further be electrically connected to a regional power distribution system, for example, an alternating current (AC) regional power distribution system.

[0090] In some embodiments, the method of the present invention can comprise the step of instructing to recharge the flow battery after discharge. The flow battery can be discharged and recharged after the useful life of the ion exchange membrane is used. In some embodiments, the method of the present invention can comprise the step of instructing to recharge the flow battery after discharge. The flow battery can be discharged and recharged after the useful life of the ion exchange membrane is used. In other embodiments, the method of the present invention can further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after the discharge of the flow battery. The electrolyte can be extracted as a used electrolyte and replaced with a new electrolyte for rapid charging. The used electrolyte can be recharged for further use. In other embodiments, the method of the present invention can further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after the discharge of the flow battery. The electrolyte can be extracted as a used electrolyte and replaced with a new electrolyte for rapid charging. The used electrolyte can be recharged for further use. In other embodiments, the method of the present invention can further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after the discharge of the flow battery. The electrolyte can be extracted as a used electrolyte and replaced with a new electrolyte for rapid charging. The used electrolyte can be recharged for further use. In other embodiments, the method of the present invention can further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after the discharge of the flow battery. The electrolyte can be extracted as a used electrolyte and replaced with a new electrolyte for rapid charging. The used electrolyte can be recharged for further use. In other embodiments, the method of the present invention can further comprise the step of instructing to replace at least one of the first electrolyte and the second electrolyte after the discharge of the flow battery. The electrolyte can be extracted as a used electrolyte and replaced with a new electrolyte for rapid charging. The used electrolyte can be recharged for further use.

[0091] The functions and advantages of these and other embodiments can be better understood from the following examples. These examples are intended to be illustrative in nature and should not be considered as limiting the scope of the present invention. In the following examples, an ion exchange membrane having desired quality is produced by coating a microporous substrate with a polymerization product. The functions and advantages of these and other embodiments can be better understood from the following examples. These examples are intended to be illustrative in nature and should not be considered as limiting the scope of the present invention. In the following examples, an ion exchange membrane having desired quality is produced by coating a microporous substrate with a polymerization product. The functions and advantages of these and other embodiments can be better understood from the following examples. These examples are intended to be illustrative in nature and should not be considered as limiting the scope of the present invention. In the following examples, an ion exchange membrane having desired quality is produced by coating a microporous substrate with a polymerization product. The functions and advantages of these and other embodiments can be better understood from the following examples. These examples are intended to be illustrative in nature and should not be considered as limiting the scope of the present invention. In the following examples, an ion exchange membrane having desired quality is produced by coating a microporous substrate with a polymerization product.

Example

[0092] Example 1: Preparation of Test Samples Laboratory research was conducted to design a method for preparing and using an ion exchange membrane. This laboratory research included the steps of creating small coupons (cut specimens) of the membrane and performing resistivity tests and co-ion transport tests on these coupons. Laboratory research was conducted to design a method for preparing and using an ion exchange membrane. This laboratory research included the steps of creating small coupons (cut specimens) of the membrane and performing resistivity tests and co-ion transport tests on these coupons. Laboratory research was conducted to design a method for preparing and using an ion exchange membrane. This laboratory research included the steps of creating small coupons (cut specimens) of the membrane and performing resistivity tests and co-ion transport tests on these coupons.

[0093] The porous membrane substrate was die-cut into coupons with a diameter of 43 mm. Transparent polyester sheets of larger disks (50 mm and 100 mm in diameter) were also die-cut. A 105 mm aluminum weighing pan was used to hold the set of coupons. The coupons were sandwiched between two polyester membrane disks.

[0094] First, the substrate coupons were completely wetted with the monomer solution to create test samples. This wetting was achieved by adding the prepared solution to the aluminum pan and immersing the polyester membrane disk with the substrate coupon into the solution, ultimately saturating the porous support. The saturated support was removed from the monomer solution and placed on one piece of polyester membrane. Bubbles were removed from the coupon by smoothing or squeezing the coupon. Bubbles can be removed with a convenient tool such as a small glass rod or by hand.

[0095] The second polyester disk was laminated on top of the first coupon and smoothed to create complete surface contact between the coupon and the lower and upper polyester membrane layers. The second porous substrate was laminated on top of the upper polyester membrane, repeating the previous steps (saturation, smoothing, and adding a cover layer of polyester membrane) to create a multi-layer sandwich of two coupons and two polyester membrane layers.

[0096] Typical experimental runs had multi-layer sandwiches of 10 or more saturated substrate coupon layers. The rim of the aluminum pan could be curled downwards to hold the disk / coupon assembly as needed.

[0097] The receptacle and assembly were then placed into a sealable bag later. Here, they were placed into a polyethylene bag of the jig block. A low positive pressure of an inert gas, here nitrogen, was added before sealing the bag. The bag containing the receptacle and coupon assembly was placed into an oven at 80 °C until it reached approximately 60 minutes. The bag was then removed and cooled . Next, the reacted ion exchange membrane coupon was placed into a 0.5 M NaCl solution at 40 °C to 50 °C for at least 30 minutes, and the immersion in the NaCl solution lasted up to 18 hours.

[0098] Therefore, the laboratory membrane coupon is suitable for ion exchange membrane testing.

[0099] Example 2: Preparation of an ion exchange membrane having UHMWPE Samples were prepared to determine the compatibility of ultra-high molecular weight polyethylene (UHMWPE) as a membrane substrate material.

[0100] The monomer mixture was incorporated into the polymerization product having a solvent as described herein. A 25-μm thick porous film (membrane) made of UHMWPE having a porosity of at least 35% and a pore diameter between 50 nm and 10 μm was saturated in the polymerization product for about 30 to 60 seconds. The saturated film (membrane) was placed between Mylar® sheets (DuPont Teijin Films / Chester, Virginia) to prevent oxygen ingress. The Mylar® sheets were clamped in place, and the film was heated to 80 °C for 30 minutes.

[0101] The permeability test was performed by placing the membrane in a test cell. A 0.5 M solution of CuSO 4 A liquid was added to one side of the membrane, and a 0.5 M solution of NaCl was added to the opposite side of the membrane. Gas A ket was used to seal the membrane in the test cell. After 4 weeks, the NaCl solution had no detectable Cu SO 4 indicating that it was a non-permeable membrane. The resistivity was measured to be between 5.0 and 8.0 Ω·cm 2 and the co-ion transport rate was measured to be 0.95. Therefore, the membrane having a UHMWPE microporous substrate exhibits non-permeability, suitable resistivity, and high

[0102] co-ion transport rate.

[0103] Example 3: Preparation of an ion exchange membrane having polyethylene Samples were prepared to determine the compatibility of polyethylene as a membrane substrate material.

[0104] The monomer mixture was incorporated into the polymerization product having a solvent as described herein . A 25-μm-thick porous film (membrane) obtained from Entek International (Newcastle upon Tyne, UK) was used as the porous substrate. This porous film had a porosity of about 35% and a pore diameter of about 200 nm (as the average value reported by the selling company). This porous film (membrane) was saturated in the polymerization product for about 30 to 60 seconds . The saturated film (membrane) was placed between Mylar (registered trademark) sheets to prevent oxygen ingress . The Mylar (registered trademark) sheets were clamped in place, and the film was heated to 80 °C for 30 minutes.

[0105] The resistivity and co-ion transport rate were measured in the same manner as in Example 2. The resistivity was measured to be between 5.0 and 8.0 Ω·cm and the co-ion transport rate was measured to be 0.95​​​ done.

[0106] Therefore, the membrane having the polyethylene microporous substrate exhibits a suitable resistivity and a high co-ion transport rate.

[0107] Example 4: Steady-State Diffusion Rate and Resistance of Exemplary Membranes The ion-exchange membrane prepared as described in Example 2 was tested for the diffusion rate with respect to Cu 2+ ions. This membrane was placed between the chambers in a two-chamber test cell. The active area of the diffusion flux was about 4.5 cm 2. 2 One chamber was filled with about 100 mL of 0.4 M CuSO 4 . The other chamber was filled with about 100 mL of 0.5 M NaCl. The chamber containing CuSO 4 was slowly stirred with a magnetic stir bar. 4 containing The 0.5 M NaCl solution was sampled by UV spectroscopy. The concentration of Cu

[0108] was determined by absorbing the solution in a quartz cuvette with a 10 mm optical path length. The instrument was "zeroed" with air as the absorption 2+ medium. This cuvette was filled with 0.5 M pure NaCl, and the absorption was recorded at a wavelength near 246 nm as the background absorption. The diffused Cu -containing 0.5 M NaCl was measured by absorption at a wavelength of 246 nm. After the absorption of pure Cu 2+ -containing 0.5 M NaCl, the Cu concentration (ppm) was obtained using the standard curve calculated according to the procedure described above. NaCl, the Cu concentration (ppm) was obtained using the standard curve calculated according to the procedure described above. m) was obtained.

[0109] Table 1 presents several membranes prepared using the method described in Example 2, where the reference sample is an AMX membrane (distributed by Asahi Kasei Corporation, Tokyo, Japan). Reference There are slight variations in the polymerization products coated on the substrate for 1 to 4.

[0110] As shown in Table 1 below, Test Films 1 to 4 have a resistivity greater than that of the reference film, but Test Films 1 to 3 have a significantly lower diffusion rate than the reference film. Furthermore, Test Films 1 to 4 are thinner than the reference film.

[0111] Therefore, Test Films 1 to 4 are superior to the reference film in terms of thickness and diffusion rate. Test Films 1 to 4 provide a more suitable resistivity.

[0112]

Table 1

[0113] Example 5: Effect of Crosslinking Agent on Resistance and Steady-State Diffusion Rate An ion exchange membrane was prepared as described in Example 2. The resistance of the membrane was tested as described in Example 2 and was 6.44 Ω·cm 2 at that time.

[0114] The polymerization product was modified so that its concentration changed by adding ethylene glycol dimethacrylate (EGDM). EGDM is a crosslinking agent based on acrylate and is available. As shown in Table 2, the addition of EGDM shows a significant change in the resistance and diffusion rate of the membrane EGDM decreases the diffusion rate but significantly increases the resistance.

[0115]

Table 2

[0116] Therefore, the addition of the crosslinking agent can generally reduce the diffusion rate of the membrane. However, crosslinking ​The agent, in some cases, tends to increase the resistivity to a non-operable level.

[0117] Example 6: Production of Ion Exchange Membrane A polymerization product was prepared as described in Example 2. The polymerization product was added to a laboratory-scale production line. The porous substrate was moved through the polymerization product solution tank and sandwiched between a pair of engaging rollers. A saturated porous film was sandwiched using two layers of Mylar® sheets. The film was moved into a heating zone that was 3.6576 m (12 feet) in total length. The heating zone consisted of four heating blocks that were independently controlled from each other and each had a length of 0.9144 m (3 feet). The film production line was operated under speed control to allow for changes in heating time. The heating zone consisted of four heating blocks that were independently controlled from each other and each had a length of 0.9144 m (3 feet). The film production line was operated under speed control to allow for changes in heating time. The film production line was operated under speed control to allow for changes in heating time. The film production line was operated under speed control to allow for changes in heating time.

[0118] Table 3 presents the membrane properties for varying heating times. All four zones were assumed to have a controlled temperature of 120 °C. The membrane produced by the production line can exhibit a suitable resistivity and a high co-ion transport rate.

Table 3

[0119] The membrane produced by the production line can exhibit a suitable resistivity and a high co-ion transport rate. The membrane produced by the production line can exhibit a suitable resistivity and a high co-ion transport rate.

[0120] Example 7: Useful Life of Ion Exchange Membrane The ion exchange membrane prepared as described in Example 2 was tested for the diffusion rate of Cu ions through the membrane. Test membranes 1 - 5 were compared to the reference membrane AMX (distributed by Asahi Kasei Corporation, Tokyo, Japan). 2+ ions Test membranes 1 - 5 were compared to the reference membrane AMX (distributed by Asahi Kasei Corporation, Tokyo, Japan). Figure 5 shows the diffusion rate of Cu ions through test membranes 1 - 5 and the reference membrane up to approximately 190 hours. It is a graph of the diffused copper concentration over a period of time that also reaches.

[0121] The initial output (power) of the test membrane was potentially slightly lower than that of the reference membrane due to the higher resistance in the test membrane (see, for example, Table 2). The test membrane initially showed a larger internal potential drop (volts), but continued for about 6000 cycles before reaching the internal potential drop threshold of 2.5V . The reference membrane continued for about 4000 cycles before reaching the internal potential drop threshold of 2.5V .

[0122] Considering the linear approximation and the test concentration (0.4M CuSO 4 ) which is about half of the operating concentration, it can be predicted that the useful life of the test membrane may be longer than 12 weeks. The useful life of the test membrane can be about 13 - 14 weeks. By conducting further experiments, it is considered that the useful life of the test membrane will increase.

[0123] The examples show that an ion exchange membrane with excellent characteristics and usefulness in flow battery applications can be produced . The examples further suggest that the membrane characteristics can be changed based on changes in chemical properties .

[0124] The language and terms used in this specification are for explanatory purposes and should not be construed as limiting. The term "plurality" as used in this specification means two or more matters or components. The terms "comprising", "including", "carrying", "having", "containing", and "involving" mean that the described specification or claims shall include the stated elements or steps and any additional elements or steps, without excluding any other elements or steps. shall include the stated elements or steps and any additional elements or steps, without excluding any other elements or steps. g)", "carrying", "having", "containing", and "involving" mean that the described specification or claims shall include the stated elements or steps and any additional elements or steps, without excluding any other elements or steps. In any of the above ranges and the like, it is not limited, that is, it means "including but not limited to". Therefore, the use of these terms means including the matters presented later, their equivalents, and additional matters. The transitional phrases "consisting of" and "consisting essentially of" are the only closed or semi-closed phrases with respect to the scope of claims. Ordinal terms such as "first", "second", "third", etc. in the scope of claims modifying claim elements do not imply any priority, precedence or order with respect to other elements of a claim element, or a temporal order of performing the acts of a method, but are used only as a label to distinguish a certain claim element with a given name from other elements with the same name (however, using ordinal terms). Although some aspects of at least one embodiment have been described, it will of course be readily apparent to those skilled in the art that various modifications, changes and improvements will occur to them. Any feature described in any embodiment can be included in or substituted for any feature in any other embodiment. Such modifications, changes and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative. Those skilled in the art will appreciate that the parameters and configurations described herein are exemplary, and the actual parameters and configurations may vary depending on the specific application or implementation. It should be noted that the scope of the claims is not limited to the specific embodiments described herein, but rather encompasses all equivalent features and variations that fall within the spirit and scope of the invention. The claims are to be construed broadly and in a manner consistent with the principles of patent law. The use of the term "first", "second", "third", etc. in the claims to modify claim elements does not imply any priority, precedence, or order among the elements of a claim or a temporal order of performing method acts. These terms are used solely to distinguish one claim element from another with the same name (while using ordinal terms). For example, in a claim that recites "a first widget and a second widget", the use of "first" and "second" does not imply that the first widget is in any way superior to or precedes the second widget in time or order. It is simply a way to differentiate between two widgets that may otherwise have the same name or function.

[0125] Although several aspects of at least one embodiment have been described, it will be readily apparent to those skilled in the art that various modifications, changes, and improvements can be made. Any feature described in any embodiment can be combined with or replaced by any feature in any other embodiment. Such modifications, changes, and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative. Any feature described in any embodiment can be combined with or replaced by any feature in any other embodiment. Such modifications, changes, and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative. Any feature described in any embodiment can be combined with or replaced by any feature in any other embodiment. Such modifications, changes, and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative. Any feature described in any embodiment can be combined with or replaced by any feature in any other embodiment. Such modifications, changes, and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative. Any feature described in any embodiment can be combined with or replaced by any feature in any other embodiment. Such modifications, changes, and improvements are intended to be part of this disclosure and within the scope of the invention. Therefore, the above description and drawings are merely illustrative.

[0126] Those skilled in the art will recognize that the parameters and configurations described herein are exemplary, and actual parameters ​​The laminator and / or configuration is based on the particular use for which the disclosed methods and materials are employed and will be understood by those skilled in the art. Those skilled in the art will further recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments disclosed herein.

Claims

**Claim 1** A method for producing an anion exchange membrane for a redox flow battery, comprising: integrating a cationic functional monomer having a crosslinking group into a polymerization product substantially free of a crosslinking agent; and coating a microporous substrate having a thickness of less than 100 μm with the polymerization product. The method is characterized in that: the cationic functional monomer is copolymerized with at least one difunctional monomer; the microporous substrate is made of polyethylene having a porosity of 35% and an average pore diameter of 200 nm. **Claim 2** The method according to claim 1, wherein the microporous substrate has a thickness of 25 μm. **Claim 3** The method according to claim 1, wherein: the difunctional monomer is selected from the group consisting of vinylbenzyltrimethylammonium chloride, trimethylammonium ethyl methacrylate chloride, methacrylamidopropyltrimethylammonium chloride, (3-acrylamidopropyl)trimethylammonium chloride, 2-vinylpyridine, and 4-vinylpyridine, and one or more polymerization initiators.

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