Heat-resistant insulating layer-provided separator containing heat-resistant resin and oxidation-resistant ceramic particles and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9583754-B2
Application number	US-21204108-A
Country	US
Kind code	B2
Filing date	Sep 17, 2008
Priority date	Oct 3, 2007
Publication date	Feb 28, 2017
Grant date	Feb 28, 2017

Abstract

A heat-resistant insulating layer-provided separator includes a polyolefin layer and a heat-resistant insulating layer formed on one or both surfaces of the polyolefin layer and containing a heat-resistant resin and an oxidation-resistant ceramic particle. The heat-resistant insulating layer contains the oxidation-resistant ceramic particle in a proportion of from 60 to 90%.

First claim

The invention is claimed as follows:

1. A non-aqueous electrolyte secondary battery comprising:
a positive electrode including a positive electrode mixture layer comprising a positive electrode active material on a positive electrode collector, wherein the positive electrode active material comprises a lithium cobalt oxide, and at least a part of the lithium cobalt oxide is coated with an oxide comprising nickel and manganese;
a negative electrode including a negative electrode mixture layer on a negative electrode collector, wherein the negative electrode mixture layer comprises artificial graphite, and a ratio of a surface density of the positive electrode mixture layer to a surface density of the negative electrode mixture layer is from 1.90 to 2.15;
a heat-resistant insulating layer-provided separator; and
a non-aqueous electrolyte comprising LiPF 6 as an electrolyte salt in a solvent of a mixture of ethylene carbonate, dimethyl carbonate, methylethyl carbonate and 4-fluoroethylene carbonate, wherein
the non-aqueous electrolyte secondary battery is configured to operate at an open circuit voltage in a completely charged state per pair of the positive electrode and the negative electrode from 4.35 V to not more than 4.55 V,
the heat-resistant insulating layer-provided separator includes a polyolefin layer disposed between the positive and negative electrodes, and a heat-resistant insulating layer comprising a heat-resistant resin and oxidation-resistant ceramic primary particles dispersed therein,
the oxidation-resistant ceramic primary particles comprise at least alumina,
the heat-resistant insulating layer comprises the oxidation-resistant ceramic primary particles in a mass proportion of from 60 to 90% of the mass of the oxidation-resistant ceramic primary particles and the heat-resistant resin, and
the heat-resistant resin is an aramid in a fibrous state.

2. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the mass proportion ranges from 80 to 90%.

3. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the mass proportion ranges from 65 to 85%.

4. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the oxidation-resistant ceramic primary particles consist of alumina.

5. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the heat-resistant resin comprises at least an aromatic polyamide.

6. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the porosity of the heat-resistant insulating layer-provided separator ranges from 35% to 50%.

7. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the heat-resistant insulating layer-provided separator comprises 10% or more by mass proportion of a thermoplastic polymer that melts at a temperature of 260° C. or less, the mass proportion being with respect to the whole heat-resistant insulating layer-provided separator.

8. The non-aqueous electrolyte secondary battery according to claim 1 , wherein the non-aqueous electrolyte secondary battery is configured to operate at an open circuit voltage in a completely charged state per pair of a positive electrode and a negative electrode of not more than 4.45 V.

Assignees

• Obana Yoshiaki
• Kajita Atsushi
• Teshima Yukako
• Ogawa Kenichi
• Tsujimoto Hisashi
• Sony Corp

Inventors

• Obana Yoshiaki
• Kajita Atsushi
• Teshima Yukako
• Ogawa Kenichi
• Tsujimoto Hisashi

Classifications

• H01M2/166

  Electricity · mapped topic

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M4/0404 Primary

  by coating on electrode collectors · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M50/446 Primary

  Composite material consisting of a mixture of organic and inorganic materials · CPC title