An electrolyte membrane and method for generating the membrane provide a resistance as low as possible to minimize ohmic losses. The membrane has a low permeability for redox-active species. If redox-active species still cross the membrane, this transport is balanced during charge and discharge preventing a net vanadium flux and associated capacity fading. The membrane is mechanically robust, chemically stable in electrolyte solution, and low cost. A family of ion exchange membranes including a bilayer architecture achieves these requirements. The bilayer membrane includes two polymers, i) a polymer including N-heterocycles with electron lone pairs acting as proton acceptor sites and ii) a mechanically robust polymer acting as a support, which can be a dense cation exchange membrane or porous support layer. This bilayer architecture permits a very thin polymer film on a supporting polymer to minimize ohmic resistance and tune electrolyte transport properties of the membrane.

An electrolyte membrane and method for generating the membrane provide a resistance as low as possible to minimize ohmic losses. The membrane has a low permeability for redox-active species. If redox-active species still cross the membrane, this transport is balanced during charge and discharge preventing a net vanadium flux and associated capacity fading. The membrane is mechanically robust, chemically stable in electrolyte solution, and low cost. A family of ion exchange membranes including a bilayer architecture achieves these requirements. The bilayer membrane includes two polymers, i) a polymer including N-heterocycles with electron lone pairs acting as proton acceptor sites and ii) a mechanically robust polymer acting as a support, which can be a dense cation exchange membrane or porous support layer. This bilayer architecture permits a very thin polymer film on a supporting polymer to minimize ohmic resistance and tune electrolyte transport properties of the membrane.

Disclosed are a micropore-filled amphoteric membrane for low vanadium ion permeability, a method of manufacturing the same, and a vanadium redox flow battery including the amphoteric membrane. The micropore-filled amphoteric membrane for low vanadium ion permeability minimizes crossover of vanadium ions, which occurs between a catholyte and an anolyte in a redox flow battery, and has low membrane resistance and thus has remarkably improved performance as compared to commercially available ion-exchange membranes such as Nafion, and accordingly, can be effectively used in the manufacture of a redox flow battery. In addition, the micropore-filled amphoteric membrane is continuously manufactured through a roll-to-roll process, and thus the manufacturing process is simple and manufacturing costs can be greatly reduced.

A zinc iodine flow battery includes a positive end plate, a positive current collector, a negative current collector, a positive electrode with a flow frame, a membrane, a negative electrode with a flow frame, a negative end plate. The negative electrolyte is circulated between the negative storage tank and the negative cavity by pump. The negative pipe is provided with a branch pipe for the positive electrolyte circulation. The porous membrane between the positive and negative electrodes can realize the conduction of supporting electrolyte and prevent the diffusion of I3− to the negative electrolyte. In a duel-flow battery system, same electrolyte serves as both the positive electrolyte and the negative electrolyte, which is a mixed aqueous solution containing iodized and zinc salt. The membrane is porous membrane does not contain ion exchange group. Both the positive and negative electrolyte are neutral solutions.

The present invention relates to an ion exchange membrane and an energy storage device comprising same, wherein the ion exchange membrane comprises: a polymer membrane comprising an ion conductor; and any one ion permeation inhibiting additive selected from the group consisting of a columnar porous metal oxide, crown ether, a nitrogen-containing cyclic compound, and a mixture thereof. In the ion exchange membrane, the size of a channel through which ions permeate is limited or an additive capable of trapping ions is introduced into an ion movement path, so that the permeation of ions is prevented, leading to the improvement of voltage efficiency and the prevention of deterioration.

A cationic copolymer comprises the divalent monomer units: wherein: each Ar.sup.1 independently represents phenylene; each L independently represents a direct bond or wherein each R.sup.1 independently represents an alkyl group having 1 to 4 carbon atoms, and each R.sup.2 independently represents an alkylene group having from 1 to 6 carbon atoms, and each Z.sup.− represents a non-interfering anion; each Ar.sup.2 independently represents an optionally substituted divalent aryl ring, with the proviso that if L represents a direct bond, then Ar.sup.2 represents an optionally substituted cationic divalent aryl ring accompanied by Z; each R.sup.3 independently represents H or an alkyl group having 1 to 6 carbon atoms; and each D independently represents a direct bond or Ar.sup.2, wherein adjacent D and L are not both direct bonds, and wherein if L is a direct bond, then D is Ar.sup.2. The cationic copolymer can be free-radially cured and used in a membrane.

A proton-conducting polymer comprises a plurality of repeating units of formula (I) for electrochemical reactions. The polymer may be synthesized from a super acid catalyzed polyhydroxyalkylation reaction of monomers Ar.sub.1′, Ar.sub.2′, and X.sub.1′ followed by a nucleophilic substitution reaction or a grafting reaction, and optionally an acidification reaction.

##STR00001##

Proton-exchange membranes and membrane electrode assemblies made from the polymer are also described.

A polyaromatic electrolyte for a fuel cell electrode includes a structure represented by Formula 1, wherein in Formula 1, Ar is a neutral unit represented by one of Formula 2A and Formula 2B: ##STR00001##
The fuel cell electrode may include a catalyst suspended in the polyaromatic electrolyte.

A polyaromatic electrolyte for a fuel cell electrode includes a structure represented by Formula 1, wherein in Formula 1, Ar is a neutral unit represented by one of Formula 2A and Formula 2B: ##STR00001##
The fuel cell electrode may include a catalyst suspended in the polyaromatic electrolyte.

Provided is an electrolyte membrane including at least the following: an A-layer composed of an ion-conducting fluorinated polymer and a non-ion-conducting fluorinated polymer; and a B-layer composed of an ion-conducting hydrocarbon polymer, wherein the ion-conducting hydrocarbon polymer is dispersed in the A-layer. Provided is an electrolyte membrane having excellent oxidation resistance. In addition, provided is an electrolyte membrane for a redox-flow battery, in which the electrolyte membrane used as a barrier membrane for a redox-flow battery makes it possible to achieve high power efficiency and stable charge and discharge even in long-term use.