Rectangular electricity storage device and method for producing rectangular electricity storage device

Patent metadata

Field	Value
Publication number	US-2017047571-A1
Application number	US-201515306909-A
Country	US
Kind code	A1
Filing date	Apr 28, 2015
Priority date	May 2, 2014
Publication date	Feb 16, 2017
Grant date	—

Abstract

A rectangular electricity storage device includes a prism-shaped electrode group with an upper surface, a lower surface, and four lateral surfaces, the electrode group including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; an electrolyte; a case with an opening portion, the ease housing the electrode group and the electrolyte; a cover plate covering the opening portion of the case; and an insulation sheet interposed between the electrode group and the case, and insulating the electrode group and the case from each other, wherein the insulation sheet is folded so as to surround the lower surface and the four lateral surfaces of the electrode group.

First claim

1 . A rectangular electricity storage device comprising:
a prism-shaped electrode group with an upper surface, a lower surface, and four lateral surfaces, the electrode group including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; an electrolyte; a case with an opening portion, the case housing the electrode group and the electrolyte; a cover plate covering the opening portion of the case; and an insulation sheet interposed between the electrode group and the case, and electrically insulating the electrode group and the case from each other, wherein the insulation sheet is folded so as to surround the lower surface and the four lateral surfaces of the electrode group.

2 . The rectangular electricity storage device according to claim 1 , wherein the insulation sheet does not have any welded portion that joins together one portion and another portion of the insulation sheet.

3 . The rectangular electricity storage device according to claim 1 , wherein the insulation sheet in its unfolded state has a shape of a rectangle, and includes
a first region including a central portion of the rectangle and covering the lower surface of the electrode group, second regions individually folded back along two opposite sides of the lower surface so as to cover two lateral surfaces out of the four lateral surfaces, and third regions folded back along other two opposite sides of the lower surface and along boundaries between the four lateral surfaces so as to cover other two lateral surfaces out of the four lateral surfaces.

4 . The rectangular electricity storage device according to claim 1 , comprising:
a positive-electrode external terminal and a negative-electrode external terminal that are electrically insulated from each other and disposed on the cover plate; a positive-electrode lead piece electrically connecting the positive electrode and the positive-electrode external terminal to each other; a negative-electrode lead piece electrically connecting the negative electrode and the negative-electrode external terminal to each other; and an insulating partition member disposed between the electrode group and the cover plate, wherein the partition member includes a bottom plate disposed so as to face the electrode group, and at least one upright plate disposed so as to extend from a periphery of the bottom plate, the bottom plate includes a first opening through which the positive-electrode lead piece extends, and a second opening through which the negative-electrode lead piece extends, and the at least one upright plate is interposed between the case and at least one lead piece out of the positive-electrode lead piece and the negative-electrode lead piece.

5 . A method for producing a rectangular electricity storage device, the method comprising:
(a) a step of preparing a prism-shaped electrode group with an upper surface, a lower surface, and four lateral surfaces, the electrode group including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode; (b) a step of preparing an electrolyte; (c) a step of preparing a case with an opening portion, the case being used for housing the electrode group and the electrolyte; (d) a step of preparing a cover plate for covering the opening portion of the case; (e) a step of preparing an insulation sheet for being interposed between the electrode group and the case so as to electrically insulate the electrode group and the case from each other; (f) a step of folding the insulation sheet so as to surround the lower surface and the four lateral surfaces of the electrode group; and (g) a step of placing the electrode group and the folded insulation sheet into the case such that the insulation sheet is interposed between the electrode group and the case.

6 . The method for producing a rectangular electricity storage device according to claim 5 , wherein the insulation sheet has a shape of a rectangle including first sides and second sides orthogonal to the first sides,
the lower surface of the electrode group has a shape of a rectangle including long sides and short sides, the first sides of the insulation sheet are longer than the long sides of the lower surface, and the step (f) includes contacting the lower surface and the insulation sheet to each other such that the long sides of the lower surface are orthogonal to the second sides of the insulation sheet, and a center of the lower surface is positioned at a center of the insulation sheet, folding back the insulation sheet individually along the two long sides of the lower surface, folding back the insulation sheet individually along the two short sides of the lower surface, and folding back the insulation sheet along boundaries between the four lateral surfaces.

Assignees

• Sumitomo Electric Industries

Inventors

• Iwasaki Mizuo
• Mochida Yasushi
• Araya Takeshi

Classifications

• H01M10/0413 Primary

  Large-sized flat cells or batteries for motive or stationary systems with plate-like electrodes · CPC title

• H01M50/593

  Spacers; Insulating plates · CPC title

• H01M50/586

  inside the batteries, e.g. incorrect connections of electrodes · CPC title

• H01M50/103 Primary

  prismatic or rectangular (H01M50/109, H01M50/11 take precedence) · CPC title

• H01M50/119

  Metals · CPC title