Bipolar electrode for metal hydride battery, metal hydride battery equipped with bipolar electrode, method for producing bipolar electrode for metal hydride battery, and method for producing metal hydride battery

Patent metadata

Field	Value
Publication number	US-2024213461-A1
Application number	US-202218288255-A
Country	US
Kind code	A1
Filing date	Apr 27, 2022
Priority date	Apr 28, 2021
Publication date	Jun 27, 2024
Grant date	—

Abstract

A bipolar electrode ( 100 ) for a metal hydride battery includes a current collector ( 10 ), a negative electrode active material layer ( 20 ) provided on a first surface ( 10 A) of the current collector ( 10 ), and a positive electrode active material layer ( 30 ) provided on a second surface ( 10 B) of the current collector ( 10 ). The negative electrode active material layer ( 20 ) contains a metal hydride. The current collector ( 10 ) includes a steel sheet ( 13 ) and a Ni—Fe alloy layer ( 15 ) formed on at least one surface of the steel sheet ( 13 ).

First claim

1 . A bipolar electrode for a metal hydride battery, the bipolar electrode comprising:
a current collector including a first surface and a second surface opposite to the first surface; a negative electrode active material layer provided on the first surface; and a positive electrode active material layer provided on the second surface, wherein the negative electrode active material layer contains a metal hydride, and the current collector includes a steel sheet and a Ni—Fe alloy layer formed on at least one surface of opposite surfaces of the steel sheet.

2 . The bipolar electrode for a metal hydride battery according to claim 1 , wherein the Ni—Fe alloy layer has a thickness of 1.0 μm or more.

3 . The bipolar electrode for a metal hydride battery according to claim 1 , wherein the Ni—Fe alloy layer is disposed on a same side as the first surface of the current collector.

4 . The bipolar electrode for a metal hydride battery according to claim 1 , wherein the Ni—Fe alloy layer is disposed on each of a same side as the first surface of the current collector and a same side as the second surface of the current collector.

5 . The bipolar electrode for a metal hydride battery according to claim 1 , wherein the current collector further includes a Ni layer between the Ni—Fe alloy layer disposed on a same side as the first surface of the current collector and the negative electrode active material layer.

6 . The bipolar electrode for a metal hydride battery according to claim 1 , wherein the current collector further includes a Ni layer between the Ni—Fe alloy layer disposed on a same side as the second surface of the current collector and the positive electrode active material layer.

7 . The bipolar electrode for a metal hydride battery according to claim 5 , wherein a surface of the Ni layer that is in contact with the negative electrode active material layer or with the positive electrode active material layer has a larger surface roughness than the Ni—Fe alloy layer or the steel sheet.

8 . The bipolar electrode for a metal hydride battery according to claim 7 , wherein, when expressed in a ten point height of irregularities Rzjis, the surface roughness of the Ni layer is in a range of 2.0 μm to 16.0 μm.

9 . A metal hydride battery, comprising multiple bipolar electrodes stacked, wherein each of the bipolar electrodes is the bipolar electrode according to claim 1 .

10 . The metal hydride battery according to claim 9 , wherein the positive electrode active material layer contains nickel hydroxide.

11 . A method for producing a bipolar electrode for a metal hydride battery, the method comprising:
a step of forming a current collector including a steel sheet and a Ni—Fe alloy layer, including providing a Ni layer on at least one of opposite surfaces of the steel sheet, and heat-treating the steel sheet on which the Ni layer is provided to diffuse Ni in the Ni layer and Fe in the steel sheet, thereby forming the Ni—Fe alloy layer; a step of forming a negative electrode active material layer on a first surface of the formed current collector; and a step of providing a positive electrode active material layer on a second surface of the current collector.

12 . The method for producing a bipolar electrode for a metal hydride battery according to claim 11 , wherein the step of forming the current collector further includes forming a roughened Ni layer on the Ni—Fe alloy layer, the roughened Ni layer having a larger surface roughness than the Ni—Fe alloy layer or a larger surface roughness than the steel sheet.

13 . A method for producing a metal hydride battery, the method comprising:
a step of producing a bipolar electrode by the production method according to claim 11 ; and
a step of producing a metal hydride battery by using the bipolar electrode.

Assignees

• Toyota Jidoshokki Kk
• Toyota Motor Co Ltd

Inventors

• CHUJO Yuki
• Nakamura Tomohiro
• Matsuura Kyohei
• KAWABATA Yutaro
• Hirose Takayuki
• Okuda Motoaki
• Okanishi Takeo
• Okumura Motoyoshi
• Kaiya Hiroyuki
• Kodama Masashi
• Terashima Daiki
• Ouchi Masanobu
• Yoshioka Koh
• Horie Shinichirou
• Koyanagi Toshifumi

Classifications

• H01M2004/029

  Bipolar electrodes · CPC title

• H01M10/345

  Gastight metal hydride accumulators · CPC title

• H01M4/669

  Steels · CPC title

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title