Polymer electrolyte membrane for medium and high temperature, preparation method thereof and high temperature polymer electrolyte membrane fuel cell comprising the same

Patent metadata

Field	Value
Publication number	US-2021119237-A1
Application number	US-202016859712-A
Country	US
Kind code	A1
Filing date	Apr 27, 2020
Priority date	Oct 16, 2019
Publication date	Apr 22, 2021
Grant date	—

Abstract

The present disclosure relates to a polymer electrolyte membrane for medium and high temperature, a preparation method thereof and a high-temperature polymer electrolyte membrane fuel cell including the same, more particularly to a technology of preparing a composite membrane including an inorganic phosphate nanofiber incorporated into a phosphoric acid-doped polybenzimidazole (PBI) polymer membrane by adding an inorganic precursor capable of forming a nanofiber in a phosphoric acid solution when preparing phosphoric acid-doped polybenzimidazole and using the same as a high-temperature polymer electrolyte membrane which is thermally stable even at high temperatures of 200-300° C. without degradation of phosphoric acid and has high ion conductivity.

First claim

What is claimed is:

1 . A composite membrane comprising:
a phosphoric acid-doped polybenzimidazole (PBI) polymer membrane; and a nanofiber incorporated into the polymer membrane, wherein the nanofiber comprises one or more phosphate selected from cerium phosphate and thorium phosphate.

2 . The composite membrane according to claim 1 , wherein the one or more phosphate selected from cerium phosphate and thorium phosphate is comprised in an amount of 1-99 wt % based on the phosphoric acid-doped PBI.

3 . A high-temperature polymer electrolyte membrane comprising the composite membrane according to claim 1 .

4 . A membrane electrode assembly for a fuel cell, comprising the high-temperature polymer electrolyte membrane according to claim 3 .

5 . A fuel cell system comprising the membrane electrode assembly according to claim 4 .

6 . The fuel cell system according to claim 5 , wherein the fuel cell is a direct liquid organic hydrogen carrier (LOHC) fuel cell.

7 . The fuel cell system according to claim 6 , wherein the liquid organic hydrogen carrier is one or more selected from: a C 1 -C 3 organic compound comprising methanol (CH 3 OH), dimethyl ether (C 2 H 6 O) and 2-propanol (C 3 H 8 O); a C 4 or higher organic compound comprising N-ethylcarbazole (NEC), biphenyl, diphenylmethane, methylcyclohexane (MCH) and dibenzyltoluene (DBT); and an inorganic compound comprising ammonia (NH 3 ), nitrohydrazine (N 2 H 4 ), hydrazine borane (N 2 H 4 BH 3 ) and ammonia borane (NH 3 BH 3 ).

8 . An electrical device comprising the fuel cell system according to claim 6 , wherein the electrical device is one or more selected from an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric boat, electric train, an aircraft, an unmanned aircraft, an electric power motor, a stationary power generator, a mobile power generator and a power storage device.

9 . A method for preparing a composite membrane, comprising:
(a) mixing a phosphoric acid-doped PBI polymer solution and a precursor solution of an inorganic precursor dissolved in phosphoric acid; and (b) forming the resulting mixture into a membrane, wherein the inorganic precursor is one or more selected from cerium phosphate and thorium phosphate.

10 . The method for preparing a composite membrane according to claim 9 , wherein the phosphoric acid-doped PBI polymer solution is synthesized by reacting 3,3′-diaminobenzidine, terephthalic acid and polyphosphoric acid at 100-400° C. under inert gas atmosphere and adding phosphoric acid when the reaction solution becomes viscous.

11 . The method for preparing a composite membrane according to claim 9 , wherein
the precursor solution is a cerium precursor solution dissolved in phosphoric acid, and, in the cerium precursor solution dissolved in phosphoric acid, the phosphoric acid and the cerium precursor are mixed weight ratio of 1:0.01-0.09.

12 . The method for preparing a composite membrane according to claim 9 , wherein 1-99 wt % of the inorganic precursor is mixed based on the phosphoric acid-doped PBI polymer.

13 . The method for preparing a composite membrane according to claim 9 , wherein, the mixing in (a) is performed at 150-300° C.

14 . The method for preparing a composite membrane according to claim 9 , wherein, in (b), a composite membrane is formed by casting the mixture of (a) onto a substrate and then hydrolyzing the cast membrane under humidified condition.

15 . The method for preparing a composite membrane according to claim 14 , wherein the hydrolysis in (b) is performed at 30-100° C. under relative humidity of 50-100% RH for 10-48 hours.

16 . The method for preparing a composite membrane according to claim 9 , wherein
the PBI polymer solution is synthesized by reacting 3,3′-diaminobenzidine, terephthalic acid and polyphosphoric acid at 100-400° C. under inert gas atmosphere and adding phosphoric acid when the reaction solution becomes viscous, the 3,3′-diaminobenzidine, the terephthalic acid, the polyphosphoric acid and the phosphoric acid are mixed at a weight ratio of 1:0.4-1:35-50:10-20, the inert gas is argon gas, the reaction is conducted by (i) stirring for 10-30 hours at a first heat-treating temperature of 100-190° C. and (ii) stirring for 20-100 minutes at a second heat-treating temperature of 195-300° C., the precursor solution is a cerium precursor solution dissolved in phosphoric acid, in the cerium precursor solution dissolved in phosphoric acid, the phosphoric acid and the cerium precursor are mixed at a weight ratio of 1:0.01-0.09, the cerium precursor is cerium sulfate tetrahydrate, the cerium precursor is mixed in an amount of 10-90 wt % based on the PBI, (a) is performed by mixing at 150-300° C., in (b), a composite membrane is formed by casting the mixture of (a) onto a substrate and then hydrolyzing the cast membrane under humidified condition, and the hydrolysis in (b) is performed at 30-100° C. under relative humidity of 50-100% RH for 10-48 hours.

Assignees

• Korea Inst Sci & Tech

Inventors

• Lee So Young
• Lee Seung Ju
• Lee Min Jae
• Park Hyun Seo
• Jang Jong Hyun
• Kim Hyoung-Juhn
• Nam Suk Woo
• Jo Young Suk
• Kim Yeong Cheon

Classifications

• H01M8/1088

  Chemical modification, e.g. sulfonation · CPC title

• H01M8/1013

  Other direct alcohol fuel cells [DAFC] · CPC title

• H01M8/1011

  Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC] · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title