Electrolyte membrane and method for producing same

Patent metadata

Field	Value
Publication number	US-11276871-B2
Application number	US-201716320354-A
Country	US
Kind code	B2
Filing date	May 31, 2017
Priority date	Jul 25, 2016
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

To provide an electrolyte membrane that exhibits high proton conductivity even at low humidity, the electrolyte membrane includes a composite membrane including: a microporous polyolefin membrane that has an average pore diameter of 1 to 1000 nm and a porosity of 50 to 90% and that can be impregnated with a solvent having a surface free energy of 28 mJ/m 2 or more, and an electrolyte containing a perfluorosulfonic acid polymer having an EW of 250 to 850 loaded into the pores of the microporous polyolefin membrane, wherein the membrane thickness of the composite membrane is 1 to 20 μm.

First claim

The invention claimed is:

1. An electrolyte membrane comprising a composite membrane comprising:
a microporous polyolefin membrane consisting of polyethylene, that has an average pore diameter of 1 to 1000 nm and a porosity of 50 to 90% and that can be impregnated with a solvent having a surface free energy at 20° C. of 33 mJ/m 2 or more, without carrying out a forced loading process under an increased or decreased pressure and without implementing hydrophilization treatment; and
an electrolyte containing a perfluorosulfonic acid polymer having an EW of 250 to 650 loaded into the pores of the microporous polyolefin membrane; wherein
the membrane thickness of the composite membrane is 1 to 20 μm.

2. The electrolyte membrane according to claim 1 , wherein the average pore diameter is 5 to 100 nm.

3. The electrolyte membrane according to claim 1 , wherein the porosity is 50 to 78%.

4. The electrolyte membrane according to claim 1 , wherein the microporous polyolefin membrane can be impregnated with a solvent having a surface free energy at 20° C. of 33 to 37 mJ/m 2 .

5. The electrolyte membrane according to claim 1 wherein the electrolyte contains a perfluorosulfonic acid polymer having an EW of 450 to 650.

6. The electrolyte membrane according to claim 1 wherein the membrane thickness of the composite membrane is 5 to 12 μm.

7. The electrolyte membrane according to claim 1 wherein the electrolyte membrane is used as an electrolyte membrane for a solid polymer fuel cell, electrolysis of water or soda electrolysis.

8. A method of manufacturing the electrolyte membrane of claim 1 comprising the following steps:
impregnating a microporous polyolefin membrane consisting of polyethylene, that has an average pore diameter of 1 to 1000 nm and a porosity of 50 to 90% and that can be impregnated with a solvent having a surface free energy at 20° C. of 33 mJ/m 2 or more, without carrying out a forced loading process under an increased or decreased pressure and without implementing hydrophilization treatment, with a solution comprising an electrolyte including a perfluorosulfonic acid polymer having an EW of 250 to 650 dissolved in a solvent;
removing the solvent by drying the microporous polyolefin membrane after the impregnation step; and
annealing the microporous polyolefin membrane after the removing step.

9. The electrolyte membrane according to claim 2 , wherein the porosity is 50 to 78%.

10. The electrolyte membrane according to claim 1 , wherein the microporous polyolefin membrane has a Gurley value of from 30 to 90 seconds/100 cc.

11. The method according to claim 8 , wherein the microporous polyolefin membrane has a Gurley value of from 30 to 90 seconds/100 cc.

Assignees

• Tokyo Inst Tech
• Teijin Ltd
• Kanagawa Institute Of Industrial Science And Tech

Inventors

• Yamaguchi Takeo
• Oshiba Yuhei
• Ohashi Hidenori
• Tomatsu Jin
• Furuya Koji
• Ohno Takao
• Nanbu Mami

Classifications

• C08J9/28

  by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum · CPC title

• C08J9/42

  with macromolecular compounds · CPC title

• H01M8/1041

  Polymer electrolyte composites, mixtures or blends · CPC title

• H01M8/1039

  halogenated, e.g. sulfonated polyvinylidene fluorides · CPC title

• H01M8/1069

  characterised by the manufacturing processes · CPC title