Stacked secondary battery and bag-like separator

Patent metadata

Field	Value
Publication number	US-2020321588-A1
Application number	US-201716303997-A
Country	US
Kind code	A1
Filing date	May 19, 2017
Priority date	May 26, 2016
Publication date	Oct 8, 2020
Grant date	—

Abstract

Provided is a stacked secondary battery with which it is possible to prevent the phenomenon of gas generated by an electrode material or the like inside a cell accumulating between an electrode and a separator, and forming bubbles that cannot readily escape, and with which safety performance at high temperatures can be enhanced. A stacked secondary battery in which a positive electrode and a negative electrode are stacked with a bag-like separator interposed therebetween, wherein one of the positive electrode and the negative electrode is accommodated in the bag-like separator, the other of the positive electrode and the negative electrode is stacked on the bag-like separator accommodating said one electrode, and the bag-like separator has a uniaxial contraction characteristic at high temperatures and has a slit formed in a contraction direction along which the contraction coefficient of the bag-like separator is large.

First claim

1 . A stacked secondary battery comprising a positive electrode and a negative electrode, being stacked with a bag-like separator interposed therebetween, wherein
one of the positive electrode and the negative electrode is accommodated in the bag-like separator; another of the positive electrode and the negative electrode is stacked on the bag-like separator in which the one electrode is accommodated; and wherein the bag-like separator has a uniaxial contraction characteristic at a high temperature and includes a slit formed along a contraction direction with a high contraction coefficient.

2 . The stacked secondary battery according to claim 1 , wherein the bag-like separator has a rectangular shape with two sides thereof parallel to the contraction direction.

3 . The stacked secondary battery according to claim 2 , wherein a surrounding portion of the bag-like separator is formed by heat-sealing at least a part of a side substantially orthogonal to the contraction direction.

4 . The stacked secondary battery according to claim 1 , wherein the slit is formed of an overlapping portion between two sheets of separators constituting a part of the bag-like separator.

5 . The stacked secondary battery according to claim 4 , wherein the slit is formed of an overlapping portion between a first portion and a second portion, the first portion constituting a part of the bag-like separator, the second portion being adjacent to the first portion.

6 . The stacked secondary battery according to claim 5 , wherein the slit is further formed of an overlapping portion between the second portion and a third portion being adjacent to the second portion.

7 . The stacked secondary battery according to claim 4 , wherein at least a part of an overlapping portion between the two sheets of separators includes a heat-sealed portion.

8 . The stacked secondary battery according to claim 4 , wherein a thickness of each separator at an overlapping portion between the two sheets of separators is smaller than a thickness at a remaining portion of each separator.

9 . The stacked secondary battery according to claim 1 , wherein the one electrode accommodated in the bag-like separator includes a plurality of electrodes.

10 . The stacked secondary battery according to claim 9 , wherein the one electrode has a substantially rectangular shape, and the plurality of the one electrodes are accommodated in the bag-like separator in such a way that short sides of the rectangular shape are arranged substantially in parallel.

11 . The stacked secondary battery according to claim 9 , wherein the one electrode has a substantially rectangular shape, and the plurality of the one electrodes are accommodated in the bag-like separator in such a way that long sides of the rectangular shape are arranged substantially in parallel.

12 . The stacked secondary battery according to claim 11 , wherein the bag-like separator is heat-sealed at a location between the plurality of the one electrodes accommodated in the bag-like separator in such a way that long sides of the rectangular shape are arranged substantially in parallel.

13 . The stacked secondary battery according to claim 9 , wherein at least a part of an overlapping portion between the two sheets of separators at a location between the plurality of the one electrodes includes a heat-sealed portion.

14 . A bag-like separator used for a stacked secondary battery in which a positive electrode and a negative electrode are stacked, wherein
the bag-like separator has a uniaxial contraction characteristic at a high temperature, and includes a slit formed along a contraction direction with a high contraction coefficient.

15 . The bag-like separator according to claim 14 , wherein the bag-like separator has a rectangular shape with two sides parallel to the contraction direction.

16 . The bag-like separator according to claim 15 , wherein a surrounding portion of the bag-like separator is formed by heat-sealing at least a part of a side substantially orthogonal to the contraction direction.

17 . The bag-like separator according to claim 14 , wherein the slit is formed of an overlapping portion between two sheets of separators.

18 . The bag-like separator according to claim 17 , wherein the slit is formed of an overlapping portion between a first portion and a second portion, the first portion constituting a part of a separator, the second portion being adjacent to the first portion.

19 . The bag-like separator according to claim 18 , wherein the slit is further formed of an overlapping portion between the second portion and a third portion being adjacent to the second portion.

20 . The bag-like separator according to claim 17 , wherein at least a part of an overlapping portion between the two sheets of separators includes a heat-sealed portion.

21 . (canceled)

Assignees

• Nec Corp

Inventors

• Narita Kaoru
• Tamura Noriyuki
• Hattori Sadanori

Classifications

• H01M4/13 Primary

  Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof · CPC title

• H01M50/466

  U-shaped, bag-shaped or folded · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M50/46

  Separators, membranes or diaphragms characterised by their combination with electrodes · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title