Power storage device

Patent metadata

Field	Value
Publication number	US-10158101-B2
Application number	US-201314409055-A
Country	US
Kind code	B2
Filing date	May 20, 2013
Priority date	Jun 26, 2012
Publication date	Dec 18, 2018
Grant date	Dec 18, 2018

Abstract

A power storage device includes an electrode assembly, a case that houses the electrode assembly, and an insulating sheet, which insulates the electrode assembly and the case from each other. The electrode assembly has a first end face, which is orthogonal to the stacking direction, two primary faces, which are located on both sides in the stacking direction, and a tab, which extends on the first end face in the direction orthogonal to the stacking direction. The insulating sheet has a folded box shape, and further has two primary face covering portions, which respectively cover the primary faces of the electrode assembly, and non-primary-face covering portions, which cover the first end face of the electrode assembly and faces other than the primary faces thereof and are continuous with the primary face covering portions. The non-primary face covering portions overlap at least partially with each other.

First claim

The invention claimed is:

1. A power storage device comprising:
an electrode assembly with a layered structure in which a positive electrode and a negative electrode are stacked, the electrode assembly being configured to have a first end face parallel with a stacking direction, two primary faces located on both sides in the stacking direction, and a tab extending from the first end face in a direction orthogonal to the stacking direction;
a case configured to house the electrode assembly; and
an insulating sheet configured to insulate the electrode assembly from the case, wherein
the insulating sheet is shaped like a folded box, has two primary-face covering portions that cover the primary faces of the electrode assembly, and has non-primary-face covering portions that cover the first end face of the electrode assembly and faces other than the primary faces and are continuous with the primary-face covering portions,
at least one of the non-primary-face covering portions has parts that overlap in layers at least partially,
the non-primary-face covering portions include a bottom-face covering portion that covers a second end face, which is an end face opposite to the first end face of the electrode assembly, and two side-face covering portions that cover both side faces, which are two end faces orthogonal to the primary faces, and the second end face,
in the insulating sheet in a spread state, the bottom-face covering portion is continuous with the primary-face covering portions and provided between the primary-face covering portions,
in the insulating sheet in the spread state, the primary-face covering portions and the bottom-face covering portion constitute a rectangular base portion as a whole,
in the insulating sheet in the spread state, the side-face covering portions extend along sides of the base portion,
in the insulating sheet in the spread state, the insulating sheet further comprises a protruding portion configured to extend from two opposed sides of the base portion in a direction orthogonal to an extending direction of the side-face covering portions,
the insulating sheet is folded along each of boundary lines between the primary-face covering portions and the bottom-face covering portion and boundary lines between the base portion and the side-face covering portions to form a box, and
given that a length of the electrode assembly in the stacking direction is D and an extending length of the side-face covering portions from the base portion is W, the length D and the length W are set to satisfy a relationship of D/2<W≤D,
in a folded state in which the insulating sheet is folded to shape like a box, the protruding portion entirely protrudes from the primary-face covering portion in a same direction as a projecting direction of the tab, and is located between the tab and the case, and
given that a projecting length of the tab from the first end face is T 0 , and a protruding dimension of the protruding portion from the first end face is K, the length T 0 and the dimension K are set to satisfy a relationship of K≥T 0 .

2. The power storage device according to claim 1 , wherein the insulating sheet in a spread state is rectangular as a whole.

3. The power storage device according to claim 2 , wherein the insulating sheet is folded without any incision to cover each face except for the upper end of the electrode assembly.

4. The power storage device according to claim 1 , wherein, the length D and the length T 0 are set to satisfy a relationship of T 0 ≤D/2.

5. The power storage device according to claim 1 , wherein
in the insulating sheet in the spread state, the side-face covering portions have incisions formed from ends of the boundary lines between the primary-face covering portions and the bottom-face covering portion along extended lines of the boundary line, and
the side-face covering portions divided into a plurality of sections by the incisions overlap each other.

6. The power storage device according to claim 5 , wherein ends of the incisions on the side of the base portion each have a hole.

7. The power storage device according to claim 1 , wherein
the case has an opening into which the electrode assembly is inserted,
the electrode assembly surrounded by the insulating sheet is inserted into the opening to be housed in the case, and
the parts of the non-primary-face covering portions overlap in layers such that one of the parts that is continuous with the bottom-face covering portion that covers the second end face from which the electrode assembly is inserted into the case is an outermost layer of the parts.

8. The power storage device according to claim 1 , wherein
the bottom-face covering portion has parts that overlap at least partially.

9. The power storage device according to claim 8 , wherein an overlapping area of the parts of the bottom-face covering portion is in contact with an inner face of the case.

10. The power storage device according to claim 1 , wherein the insulating sheet covers a predetermined region of the first end face other than the region where the tab extends.

11. The power storage device according to claim 1 , further comprising:
an electrode terminal partially exposed from the case; and
a conductive member configured to connect the tab to the electrode terminal,
wherein, given a length of the tab and the conductive member from the first end face in the direction orthogonal to the first end face is T 1 , and a protruding dimension of the protruding portion from the first end face is K, the length D, the length T 1 , and the dimension K are set to satisfy a relationship of 0<T 1 <K<D.

12. The power storage device according to claim 1 , wherein the power storage device is a rechargeable battery.

13. The power storage device according to claim 1 , wherein the boundary lines for folding are configured to be thinner than other areas of the insulating sheet.

Assignees

• Toyota Jidoshokki Kk

Inventors

• MINAGATA Atsushi
• Okuda Motoaki
• Tomioka Masami

Classifications

• H01M10/0413 Primary

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

• H01M50/176

  for prismatic or rectangular cells (H01M50/181 takes precedence) · CPC title

• H01M50/553

  Terminals adapted for prismatic, pouch or rectangular cells · CPC title

• H01M50/55

  on the same side of the cell · CPC title

• H01M50/119

  Metals · CPC title