Negative electrode for alkaline secondary battery, and alkaline secondary battery

Patent metadata

Field	Value
Publication number	US-2019319260-A1
Application number	US-201916383048-A
Country	US
Kind code	A1
Filing date	Apr 12, 2019
Priority date	Apr 13, 2018
Publication date	Oct 17, 2019
Grant date	—

Abstract

A battery comprises an electrode group including a separator, a positive electrode and a negative electrode. The negative electrode comprises a negative electrode core, negative electrode mixture layers retained to the negative electrode core, and a fluorine resin layer disposed on the surface of the negative electrode mixture layers. The negative electrode mixture layers include a first outermost peripheral region located at the outermost periphery of the electrode group and a second outermost peripheral region located opposite to the first outermost peripheral region. When the amount of the fluorine resin constituting a first fluorine resin layer in a portion of the first outermost peripheral region is represented by A, and the amount of the fluorine resin constituting a second fluorine resin layer in a portion of the second outermost peripheral region is represented by B, a relation A>B is satisfied.

First claim

1 . A negative electrode for an alkaline secondary battery comprising a belt-like negative electrode core having conductivity, negative electrode mixture layers made of a negative electrode mixture supported on a first surface of the negative electrode core and a second surface opposite to the first surface, and a fluorine resin layer made of a fluorine resin disposed on a surface of the negative electrode mixture layer, the negative electrode combined with a positive electrode and a separator each in a belt-like shape being wound to constitute a part of a cylindrical electrode group; wherein:
the negative electrode mixture layers comprise a first negative electrode mixture layer located on a first surface side and a second negative electrode mixture layer located on a second surface side; the first negative electrode mixture layer comprises a first outermost peripheral region located at an outermost periphery of the electrode group and a first inner peripheral region extending to the first outermost peripheral region; the second negative electrode mixture layer comprises a second outermost peripheral region located opposite to the first outermost peripheral region, in a range corresponding to the first outermost peripheral region, and a second inner peripheral region located opposite to the first inner peripheral region, in a range corresponding to the first inner peripheral region; the first outermost peripheral region has a thickness thinner than that of each of the second outermost peripheral region, the first inner peripheral region and the second inner peripheral region; and the amount of the fluorine resin constituting the fluorine resin layer in a portion of the first outermost peripheral region is represented by A, and the amount of the fluorine resin constituting the fluorine resin layer in a portion of the second outermost peripheral region is represented by B, and a relation A>B is satisfied.

2 . The negative electrode for an alkaline secondary battery according to claim 1 , wherein the A is 3 times or more than the B.

3 . The negative electrode for an alkaline secondary battery according to claim 1 , wherein the fluorine resin is made of perfluoroalkoxyalkane.

4 . The negative electrode for an alkaline secondary battery according to claim 1 , wherein the negative electrode mixture comprises a hydrogen storage alloy.

5 . The negative electrode for an alkaline secondary battery according to claim 1 ,
wherein the A expressed in mass per unit mass of the negative electrode mixture in the first outermost peripheral region is in the range of 14 mg/g or more and 30 mg/g or less, and the B expressed in mass per unit mass of the negative electrode mixture in the second outermost peripheral region is in the range of 4 mg/g or more and 10 mg/g or less.

6 . An alkaline secondary battery comprising a container, and an electrode group accommodated together with an alkaline electrolyte in the container, wherein
the electrode group comprises a positive electrode and a negative electrode stacked through a separator, and the negative electrode is a negative electrode for an alkaline secondary battery according to claim 1 .

Assignees

• Fdk Corp

Inventors

• Sato Toshiki
• Ishida Jun
• Saguchi Akira
• OHATA Shota

Classifications

• H01M4/242 Primary

  Hydrogen storage electrodes · CPC title

• H01M4/32

  Nickel oxide or hydroxide electrodes · CPC title

• H01M10/286

  Cells or batteries with wound or folded electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/623

  fluorinated polymers · CPC title