Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10079386-B2
Application number	US-201414900525-A
Country	US
Kind code	B2
Filing date	Jun 10, 2014
Priority date	Jul 1, 2013
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A non-aqueous electrolyte secondary battery includes a pressure-sensitive current shut-off mechanism, wherein a positive electrode core body exposed portion is disposed at one end portion of a flat rolled electrode assembly, a negative electrode core body exposed portion is disposed at the other end portion, lithium carbonate is contained in a positive electrode mix layer, and a protective layer is disposed along the border with the positive electrode mix layer at the position opposite to a separator on the positive electrode core body exposed portion.

First claim

The invention claimed is:

1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode plate in which a positive electrode mix layer is disposed on a positive electrode core body;
a negative electrode plate in which a negative electrode mix layer is disposed on a negative electrode core body;
a positive electrode terminal electrically connected to the positive electrode plate;
a negative electrode terminal electrically connected to the negative electrode plate;
a flat rolled electrode assembly in which the positive electrode plate and the negative electrode plate in the state of being insulated from each other with a separator therebetween are rolled into a flat shape;
a non-aqueous electrolytic solution; and
an outer body,
wherein a rolled positive electrode core body exposed portion is disposed at one end portion of the flat rolled electrode assembly,
a rolled negative electrode core body exposed portion is disposed at the other end portion of the flat rolled electrode assembly,
the rolled positive electrode core body exposed portion is bundled and connected to a positive electrode collector,
the rolled negative electrode core body exposed portion is bundled and connected to a negative electrode collector,
a pressure-sensitive current shut-off mechanism is disposed in at least one of a conducting path between the positive electrode plate and the positive electrode terminal and a conducting path between the negative electrode plate and the negative electrode terminal,
lithium carbonate is contained in the positive electrode mix layer, and
a porous protective layer is disposed along the border with the positive electrode mix layer at the position opposite to the separator on at least one surface of the positive electrode core body exposed portion,
wherein the protective layer has electrical conductivity and is a protective layer having the electrical conductivity lower than that of the positive electrode core body, and
the protective layer contains lithium carbonate.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the thickness of the protective layer is less than or equal to the thickness of the positive electrode mix layer.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the protective layer is disposed adjoining the positive electrode mix layer.

4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the protective layer is disposed at the position apart from the positive electrode mix layer.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the protective layer contains at least one of alumina particles and graphite particles.

6. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the protective layer is disposed in such a way that a region not covered with the separator disposed oppositely is generated.

7. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the lithium carbonate concentration in the positive electrode mix layer is 0.1 percent by mass or more and 5 percent by mass or less relative to the mass of the positive electrode mix.

8. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the outer body is rectangular.

9. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the protective layer contains a binder, a carbon material, and at least one selected from alumina, silica, and zirconia.

10. A non-aqueous electrolyte secondary battery comprising:
a positive electrode plate in which a positive electrode mix layer is disposed on a positive electrode core body;
a negative electrode plate in which a negative electrode mix layer is disposed on a negative electrode core body;
a positive electrode terminal electrically connected to the positive electrode plate;
a negative electrode terminal electrically connected to the negative electrode plate;
a flat rolled electrode assembly in which the positive electrode plate and the negative electrode plate in the state of being insulated from each other with a separator therebetween are rolled into a flat shape;
a non-aqueous electrolytic solution; and
an outer body,
wherein a rolled positive electrode core body exposed portion is disposed at one end portion of the flat rolled electrode assembly,
a rolled negative electrode core body exposed portion is disposed at the other end portion of the flat rolled electrode assembly,
the rolled positive electrode core body exposed portion is bundled and connected to a positive electrode collector,
the rolled negative electrode core body exposed portion is bundled and connected to a negative electrode collector,
a pressure-sensitive current shut-off mechanism is disposed in at least one of a conducting path between the positive electrode plate and the positive electrode terminal and a conducting path between the negative electrode plate and the negative electrode terminal,
lithium carbonate is contained in the positive electrode mix layer, and
a porous protective layer is disposed along the border with the positive electrode mix layer at the position opposite to the separator on at least one surface of the positive electrode core body exposed portion,
wherein the porosity of the protective layer is larger than the porosity of the positive electrode mix layer.

11. A non-aqueous electrolyte secondary battery comprising:
a positive electrode plate in which a positive electrode mix layer is disposed on a positive electrode core body;
a negative electrode plate in which a negative electrode mix layer is disposed on a negative electrode core body;
a positive electrode terminal electrically connected to the positive electrode plate;
a negative electrode terminal electrically connected to the negative electrode plate;
a flat rolled electrode assembly in which the positive electrode plate and the negative electrode plate in the state of being insulated from each other with a separator therebetween are rolled into a flat shape;
a non-aqueous electrolytic solution; and
an outer body,
wherein a rolled positive electrode core body exposed portion is disposed at one end portion of the flat rolled electrode assembly,
a rolled negative electrode core body exposed portion is disposed at the other end portion of the flat rolled electrode assembly,
the rolled positive electrode core body exposed portion is bundled and connected to a positive electrode collector,
the rolled negative electrode core body exposed portion is bundled and connected to a negative electrode collector,
a pressure-sensitive current shut-off mechanism is disposed in at least one of a conducting path between the positive electrode plate and the positive electrode terminal and a conducting path between the negative electrode plate and the negative electrode terminal,
lithium carbonate is contained in the positive electrode mix layer, and
a porous protective layer is disposed along the border with the positive electrode mix layer at the position opposite to the separator on at least one surface of the positive electrode core body exposed portion,
wherein the protective layer is disposed in such a way that a region not covered with the separator disposed oppositely is generated.

12. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the porosity of the protective layer is larger than the porosity of the positive electrode mix layer.

13. The non-aqueous electrolyte secondary battery according to claim 10 , wherein the thickness of the protective layer is less than or equal to the thickness of the positiv

Assignees

• Sanyo Electric Co

Inventors

• Tode Shingo
• Fujihara Toyoki
• Nohma Toshiyuki

Classifications

• H01M4/62 Primary

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/13

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

• H01M10/052

  Li-accumulators · CPC title

• H01M10/0587 Primary

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

• H01M4/366

  as layered products · CPC title