Proton exchange membrane with enhanced chemical stability and method of preparing thereof

Patent metadata

Field	Value
Publication number	US-2020343569-A1
Application number	US-201916690139-A
Country	US
Kind code	A1
Filing date	Nov 21, 2019
Priority date	Apr 29, 2019
Publication date	Oct 29, 2020
Grant date	—

Abstract

polymeric ion-conducting membrane with an enhanced stability against attacks of free radicals for exteding its service time, which comprises (a) a polymer matrix, and (b) a redox stabilizer, where the redox stabilizer is attached to the polymer matrix by chemical or ligand bonding, or the redox stabilizer is physically mixed with the polymer matrix.

First claim

We claim:

1 . A polymeric ion-conducting membrane with an enhanced stability against attacks of free radicals, comprising:
(a) a polymer matrix, and (b) a redox stabilizer wherein said redox stabilizer is attached to said polymer matrix by chemical or ligand bonding, or said redox stabilizer is physically mixed with said polymer matrix.

2 . The polymeric ion-conducting membrane of claim 1 , wherein said redox stabilizer is one or more molecules each independently comprising a ferrocyanide or a ferricyanide group.

3 . The polymeric ion-conducting membrane of claim 2 , wherein said molecule comprising a ferrocyanide or a ferricyanide group is selected from the group consisting of potassium ferrocyanide, sodium ferrocyanide, ammonium ferrocyanide, potassium ferricyanide, sodium ferricyanide, ammonium ferricyanide, hexacyanoferrous acid, hexacyanoferric acid, potassium nitroprusside, sodium nitroprusside, sodium pentacyanoammineferroate, and ammonium disodium pentacy anoammineferroate.

4 . The polymeric ion-conducting membrane of claim 3 , wherein said molecule comprises a ferrocyanide or a ferricyanide group is potassium ferricyanide or sodium pentacy anoammineferrate.

5 . The polymeric ion-conducting membrane of claim 1 , wherein said redox stabilizer is a hydroquinone-based molecule that undergoes a redox cycle.

6 . The polymeric ion-conducting membrane of claim 5 , wherein said is selected from the group consisting of hydroquinone, benzoquinone, naphthoquinone, phenanthraquinone, anthraquinone and all their related derivatives.

7 . The polymeric ion-conducting membrane of claim 1 , wherein said polymer matrix has a polymer chain architecture selected from the group consisting of homopolymer, random or block copolymer, random or block terpolymer, crosslinked polymer, interpenetrating network, and a polymer containing side chains.

8 . A method of making a proton exchange membrane, comprising:
(a) preparing a polymer matrix; (b) adding an amount of a redox stabilizer to said polymer matrix in a predetermined mass ratio to form a membrane formulation or, alternatively, attaching an amount of a redox stabilizer directly to said polymer matrix in a predetermined mass ratio by ligand or chemical bonding to from a modified polymer matrix; (c) dissolving said membrane formulation or modified polymer matrix in a solvent to afford a membrane casting solution; (d) casting said membrane casting solution and allowing the solvent evaporating therefrom to form a membrane; and (e) conducting acidification of said membrane to obtain a proton exchange membrane.

9 . The method of claim 7 , wherein said redox stabilizer is a molecule comprising a ferricyanide or a ferricyanide group.

10 . The method of claim 8 , wherein said molecule comprising a ferrocyanide or a ferricyanide group is selected from the group consisting of potassium ferrocyanide, sodium ferrocyanide, ammonium ferrocyanide, potassium ferricyanide, sodium ferricyanide, ammonium ferricyanide, hexacyanoferrous acid, hexacyanoferric acid, potassium nitroprusside, sodium nitroprusside, sodium pentacyanoammineferroate, and ammonium disodium pentacyanoammineferroate.

11 . The method of claim 7 , wherein said redox stabilizer is a hydroquinone-based molecule that undergoes a redox cycle.

12 . The method of claim 7 , where said polymer matrix is prepared from one or more ingredients selected from the group consisting of Nafion, sulfonated poly(ether ether ketone), sulfonated polysulfone, sulfonated poly(ether sulfone), sulfonated polyimide, sulfonated polybenzimidazoles, sulfonated polystyrene, sulfonated polynitrile, sulfonated polyphenylenes, sulfonated poly(phenylene oxide)s, sulfonated polyphenylene sulfide, sulfonated polyphosphazene, poly(vinyl pyridine), poly(vinyl chloride), polytetrafluoroethylene, poly(vinylidene fluoride) and copolymers of vinylidene fluoride and hexafluoropropylene.

13 . The method of claim 7 , wherein in step(b) said predetermined mass ratio of polymer matrix to redox stabilizer is (99-85):(1-15)

14 . The method of claim 13 , wherein in step(c) said solvent is selected from the group consisting of dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, diphenyl ether, hexamethylphosphoramide, hexaethylphosphoramide, ethylene glycol monophenyl ether, triethylene glycol, diethylene glycol, dimethylbenzene, dimethylphenol, tetrahydrofuran, methyltetrahydrofuran and dioxane.

15 . The method of claim 7 , wherein said evaporation in step(d) is conducted at a temperature between 20 and 160° C. and a pressure between 0 and 1 atm.

16 . The method of claim 7 , wherein said acidification in step(e) is conducted in an acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid and acetic acid.

Assignees

• Univ Tianjin

Inventors

• Yin Yan
• Zhang Junfeng
• Liu Xin
• Guiver Michael Dominic

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/1081

  starting from solutions, dispersions or slurries exclusively of polymers · CPC title

• H01M8/1051 Primary

  Non-ion-conducting additives, e.g. stabilisers, SiO2 or ZrO2 · CPC title

• H01M8/1072

  by chemical reactions, e.g. in situ polymerisation or in situ crosslinking · CPC title

• H01M8/1069

  characterised by the manufacturing processes · CPC title