Power storage device

Patent metadata

Field	Value
Publication number	US-9972821-B2
Application number	US-201314387642-A
Country	US
Kind code	B2
Filing date	Mar 26, 2013
Priority date	Mar 27, 2012
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

When an electrode assembly of a power storage device is viewed from the front in the direction of lamination, the distance between a positive electrode electricity collecting portion and an imaginary reference line passing through the center of the electrode assembly is different from the distance between a negative electrode electricity collecting portion and the imaginary reference line. Therefore, the electrode assembly has an asymmetrical structure.

First claim

The invention claimed is:

1. A power storage device, comprising:
an electrode assembly having a multi-layer structure comprising a plurality of separate and non-continuous layers stacked together, wherein the plurality of separate and non-continuous layers include positive electrode sheets and negative electrode sheets;
a battery can that accommodates the electrode assembly;
a positive electrode terminal that takes out electricity from the positive electrode sheets; and
a negative electrode terminal that takes out electricity from the negative electrode sheets, wherein
the positive electrode terminal includes:
a positive electrode internal terminal that is electrically connected with the positive electrode sheets and accommodated in the battery can; and
a positive electrode external terminal that is partially exposed outside the battery can,
each of the positive electrode sheets includes a positive electrode metallic thin plate and a positive electrode active material layer formed by coating the positive electrode metallic thin plate with a positive electrode active material,
a positive electrode electricity collecting portion that is a portion not coated with the positive electrode active material is formed on the positive electrode metallic thin plate of each of the positive electrode sheets,
the positive electrode electricity collecting portion of each of the positive electrode sheets includes a positive electrode connecting portion serving as a connection portion with the positive electrode terminal and extends from one end of the positive electrode sheets,

the negative electrode terminal includes:
a negative electrode internal terminal that is electrically connected with the negative electrode sheets and accommodated in the battery can; and
a negative electrode external terminal that is partially exposed outside the battery can,
each of the negative electrode sheets includes a negative electrode metallic thin plate and a negative electrode active material layer formed by coating the negative electrode metallic thin plate with a negative electrode active material,
a negative electrode electricity collecting portion that is a portion not coated with the negative electrode active material is formed on the negative electrode metallic thin plate of each of the negative electrode sheets,
the negative electrode electricity collecting portion of each of the negative electrode sheets includes a negative electrode connecting portion serving as a connection portion with the negative electrode terminal and extends from one end of the negative electrode sheets, wherein

the positive electrode active material layer and the negative electrode active material layer overlap in a region of the electrode assembly to form an overlapping portion of each layer of the electrode assembly,
a width direction of the overlapping portion is a direction orthogonal to a direction in which the positive electrode electricity collecting portion and the negative electrode electricity collecting portion extend, a line that passes through a center located between opposing widthwise edges of the overlapping portion of each layer in the width direction of the overlapping portion and extends in the direction in which the positive electrode electricity collecting portion and the negative electrode electricity collecting portion extend is defined as a reference line,
a width direction of the positive electrode electricity collecting portion is a direction orthogonal to a direction in which the positive electrode electricity collecting portion extends, a line that passes through a center of the positive electrode electricity collecting portion in the width direction of the positive electrode electricity collecting portion and extends in the direction in which the positive electrode electricity collecting portion extends is defined as a first central line,
a width direction of the negative electrode electricity collecting portion is a direction orthogonal to a direction in which the negative electrode electricity collecting portion extends, a line that passes through a center of the negative electrode electricity collecting portion in the width direction of the negative electrode electricity collecting portion and extends in the direction in which the negative electrode electricity collecting portion extends is defined as a second central line,
a distance between the reference line and the first central line in the width direction of the overlapping portion is different from a distance between the reference line and the second central line in the width direction of the overlapping portion, so that the electrode assembly has an asymmetric structure, and
one of the positive electrode electricity collecting portion and the negative electrode electricity collecting portion is a first electricity collecting portion, and the other one of the positive electrode electricity collecting portion and the negative electrode electricity collecting portion is a second electricity collecting portion, wherein the first electricity collecting portion is positioned nearer to the reference line than both the second electricity collecting portion and one of the positive electrode external terminal and the negative electrode external terminal that is electrically connected with the first electricity collecting portion.

2. A power storage device, comprising:
an electrode assembly having a multi-layer structure comprising a plurality of separate and non-continuous layers stacked together, wherein the plurality of separate and non-continuous layers include positive electrode sheets and a negative electrode sheets;
a battery can that accommodates the electrode assembly;
a positive electrode terminal that takes out electricity from the positive electrode sheets; and
a negative electrode terminal that takes out electricity from the negative electrode sheets, wherein
the positive electrode terminal includes:
a positive electrode internal terminal that is electrically connected with the positive electrode sheets and accommodated in the battery can; and
a positive electrode external terminal that is partially exposed outside the battery can,
each of the positive electrode sheets includes a positive electrode metallic thin plate and a positive electrode active material layer formed by coating the positive electrode metallic thin plate with a positive electrode active material,
a positive electrode electricity collecting portion that is a portion not coated with the positive electrode active material is formed on the positive electrode metallic thin plate of each of the positive electrode sheets,
the positive electrode electricity collecting portion of each of the positive electrode sheets includes a positive electrode connecting portion serving as a connection portion with the positive electrode terminal and extends from one end of the positive electrode sheets,
the negative electrode terminal includes:
a negative electrode internal terminal that is electrically connected with the negative electrode sheets and accommodated in the battery can; and
a negative electrode external terminal that is partially exposed outside the battery can,
each of the negative electrode sheets includes a negative electrode metallic thin plate and a negative electrode active material layer formed by coating the negative electrode metallic thin plate with a negative electrode active material,
a negative electrode electricity collecting portion that is a portion not coated with the negative electrode active material is formed on the negative electrode metallic thin plate of each of the negative electrode sheets,
the negative electrode electricity collecting portion of each of the negative electrode sheets includes a negative electrode connecting portion serving as a connection portion with the negative electrode terminal and extends f

Assignees

• Toyota Jidoshokki Kk

Inventors

• MINAGATA Atsushi

Classifications

• H01M50/528 Primary

  Fixed electrical connections, i.e. not intended for disconnection · CPC title

• H01M50/566

  by welding, soldering or brazing · CPC title

• H01M50/55

  on the same side of the cell · CPC title

• H01M50/54

  Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges · CPC title

• H01M50/533

  characterised by the shape of the leads or tabs · CPC title