Separator and nonaqueous electrolytic secondary battery including the same

Patent metadata

Field	Value
Publication number	US-9490462-B2
Application number	US-201213687418-A
Country	US
Kind code	B2
Filing date	Nov 28, 2012
Priority date	Dec 1, 2011
Publication date	Nov 8, 2016
Grant date	Nov 8, 2016

Abstract

A separator for a battery according to the present disclosure (present separator) is held between a positive electrode and a negative electrode of the battery and includes an inorganic layer formation part and an inorganic layer non-formation part formed at an end. In addition, a nonaqueous electrolytic secondary battery according to the present disclosure includes: an electrode assembly including: a positive electrode having an active material layer including a positive electrode active material and a positive electrode current collector foil exposure part; a negative electrode having an active material layer including a negative electrode active material and a negative electrode current collector foil exposure part; and the present separator held between the positive electrode and the negative electrode; a case for housing the electrode assembly; and an electrolyte held between the positive electrode and the negative electrode.

First claim

What is claimed is:

1. A nonaqueous electrolytic secondary battery comprising:
an electrode assembly including:
a positive electrode having an active material layer including a positive electrode active material and a positive electrode current collector foil exposure part;
a negative electrode having an active material layer including a negative electrode active material and a negative electrode current collector foil exposure part; and
a separator held between the positive electrode and the negative electrode;

a case for housing the electrode assembly; and
an electrolyte held between the positive electrode and the negative electrode,
wherein the separator comprising:
a porous resin film; and
an inorganic layer formed on a part of a surface of the porous resin film,

no inorganic layer is formed on a part at an end of the porous resin film,
the separator includes a part that does not face the negative electrode active material layer on the negative electrode current collector foil exposure part side, and a part that does not face the negative electrode active material layer on the positive electrode current collector foil exposure part side, and
a ratio of a width of the part of the porous resin film on which no inorganic layer is formed to a width of the part of the porous resin film that does not face the negative electrode active material layer on the negative electrode current collector foil exposure part side is 2% or more and 50% or less and/or a ratio of the width of the part of the porous resin film on which no inorganic layer is formed to a width of the part of the porous resin film that does not face the negative electrode active material layer on the positive electrode current collector foil exposure part side is 2% or more and 50% or less.

2. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the electrode assembly includes the positive electrode, the negative electrode, and the separator which are overlapped on one another and wound.

3. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the electrode assembly includes a stack of assemblies each including the positive electrode, the negative electrode, and the separator.

4. The nonaqueous electrolytic secondary battery according to claim 1 , wherein:
the positive electrode current collector foil exposure part of the positive electrode is formed at one end of the positive electrode in a width direction;
the negative electrode current collector foil exposure part of the negative electrode is formed at one end of the negative electrode in a width direction on a side opposite to the positive electrode current collector foil exposure part; and
the part of the porous resin film on which no inorganic layer is formed is provided to each end of the separator in a width direction.

5. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the part of the porous resin film on which the inorganic layer is formed is provided to one surface of the separator and this surface faces the positive electrode or the negative electrode.

6. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the part of the porous resin film on which the inorganic layer is formed has higher porosity than the part of the porous resin film on which no inorganic layer not formed.

7. The nonaqueous electrolytic secondary battery according to claim 6 , wherein the porosity of the part of the porous resin film on which the inorganic layer is formed is in a range of 35 to 85%.

8. The nonaqueous electrolytic secondary battery according to claim 6 , wherein the porosity of the part of the porous resin film on which no inorganic layer is formed is in a range of 30 to 80%.

9. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the inorganic layer comprises inorganic particles.

10. The nonaqueous electrolytic secondary battery according to claim 1 , wherein the inorganic layer comprises inorganic particles and a binder.

Assignees

• Gs Yuasa Int Ltd

Inventors

• Teshima Minoru
• Mori Sumio
• Miyazaki Akihiko

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M50/457

  comprising three or more layers · CPC title

• H01M50/443

  Particulate material · CPC title

• H01M50/434

  Ceramics · CPC title

• H01M50/489

  Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties · CPC title