Metal hydride-air (mh-air) battery for low cost storage applications

Patent metadata

Field	Value
Publication number	US-2016248136-A1
Application number	US-201514641168-A
Country	US
Kind code	A1
Filing date	Mar 6, 2015
Priority date	Mar 6, 2014
Publication date	Aug 25, 2016
Grant date	—

Abstract

Metal hydride-air batteries and methods for their use are provided. An exemplary metal-hydride air battery includes an alkaline exchange membrane provided between the positive electrode and the negative electrode of the battery. The alkaline exchange membrane provides for transfer of hydroxide ions through the membrane. Optionally the alkaline exchange membrane limits transport of other species through the membrane.

First claim

We claim:

1 . A metal hydride-air battery comprising:
a positive air electrode comprising an electrocatalyst; a negative electrode comprising a hydrogen absorbing material, the hydrogen absorbing material comprising a metal; an electrolyte provided between said positive electrode and negative electrode, said electrolyte being capable of conducting hydroxide charge carriers; and an alkaline exchange membrane provided between said positive electrode and said negative electrode; wherein said alkaline exchange membrane restricts transport of O 2 from said positive electrode to said negative electrode during charging or discharging of said battery.

2 . The metal hydride-air battery of claim 1 , wherein said alkaline exchange membrane comprises a polymer electrolyte.

3 . The metal hydride-air battery of claim 2 , wherein said alkaline exchange membrane comprises an ionomer.

4 . The metal hydride-air battery of claim 1 , wherein said alkaline exchange membrane is chemically stable for an electrolyte pH from 10 to 15.

5 . The metal hydride-air battery of claim 1 , wherein said hydrogen absorbing material is selected from the group consisting of an intermetallic compound or a solid solution alloy.

6 . The metal hydride-air battery of claim 1 , wherein said hydrogen absorbing material is an amorphous material.

7 . The metal hydride-air battery of claim 1 , wherein said hydrogen absorbing material is provided in physical contact with said alkaline exchange membrane.

8 . The metal hydride-air battery of claim 1 , wherein said electrocatalyst is a bifunctional electrocatalyst.

9 . The metal hydride-air battery of claim 2 , wherein the electrocatalyst is one of an oxygen reduction reaction catalyst and an oxygen evolution catalyst and the battery further comprises a second electrocatalyst, the second electrocatalyst being the other of an oxygen reduction reaction catalyst and an oxygen evolution catalyst.

10 . The metal hydride-air battery of claim 1 , wherein a source of O 2 is provided in contact with said positive electrode and said source of O 2 is air.

11 . The metal hydride-air battery of claim 1 , wherein said electrocatalyst is provided in physical contact with said alkaline exchange membrane.

12 . The metal hydride-air battery of claim 1 , wherein said alkaline exchange membrane functions as a substrate to support said electrocatalyst of said positive electrode.

13 . The metal hydride-air battery of claim 1 , wherein said electrolyte is an aqueous alkaline electrolyte.

14 . The metal hydride-air battery of claim 1 , wherein said electrolyte comprises a source of hydroxide ion dissolved in a solvent, said source of hydroxide ion selected from the group consisting of KOH and NaoH and an combination of these.

15 . The metal hydride-air battery of claim 1 , wherein said source of hydroxide ion has a concentration in said solvent selected from the range 1M to 6M.

16 . The metal hydride-air battery of claim 1 comprising a closed system.

17 . A method of generating electrical current, said method comprising:
providing a metal hydride battery comprising:
a positive air electrode comprising an electrocatalyst in contact with a source of O 2 ;
a negative electrode comprising an metal hydride active material;
an electrolyte provided between said positive electrode and negative electrode, said electrolyte capable of conducting hydroxide charge carriers; and
an alkaline exchange membrane provided between said positive electrode and said negative electrode; wherein said alkaline exchange membrane restricts transport of O 2 from said positive electrode to said negative electrode during discharging of said battery; and
discharging said battery thereby generating electrical current.

18 . A method of storing electrical current, said method comprising:
providing a metal hydride battery comprising:
a positive air electrode comprising an electrocatalyst;
a negative electrode comprising a hydrogen absorbing material, the hydrogen absorbing material comprising a metal;
an electrolyte provided between said positive electrode and negative electrode, said electrolyte capable of conducting hydroxide charge carriers; and
an alkaline exchange membrane provided between said positive electrode and said negative electrode; wherein said alkaline exchange membrane restricts transport of O 2 from said positive electrode to said negative electrode during charging of said battery; and
charging said battery by flowing current into said battery thereby storing said current as chemical energy.

Assignees

• California Inst Of Techn

Inventors

• Bugga Ratnakumar V
• Kindler Andrew
• Valdez Thomas I

Classifications

• H01M4/383

  Hydrogen absorbing alloys · CPC title

• H02J7/0052

  Electricity · mapped topic

• H01M12/08 Primary

  composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title