Nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11522197-B2
Application number	US-202016832037-A
Country	US
Kind code	B2
Filing date	Mar 27, 2020
Priority date	Apr 9, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

An object of the present invention is to provide a nonaqueous electrolyte secondary battery that allows more suitably suppressing short circuits between a positive electrode collector and a negative electrode active material layer, even when the battery generates heat. Provided is a nonaqueous electrolyte secondary battery 1 that includes a positive electrode and a negative electrode. The positive electrode includes a positive electrode collector, a positive electrode active material layer, and an insulating layer provided on another part of the surface of the positive electrode collector, so as to be adjacent to the positive electrode active material layer. The insulating layer contains an inorganic filler and a binder. A penetration strength of the insulating layer in a thickness direction perpendicular to the surface of the positive electrode collector is 0.05 N/mm 2 or higher.

First claim

What is claimed is:

1. A nonaqueous electrolyte secondary battery, comprising:
a positive electrode; a negative electrode; and a nonaqueous electrolyte, wherein the positive electrode includes
a positive electrode collector;
a positive electrode active material layer provided on part of the surface of the positive electrode collector; and
an insulating layer provided on another part of the surface of the positive electrode collector, so as to be adjacent to the positive electrode active material layer;
the insulating layer contains an inorganic filler and a binder, wherein the inorganic filler contains plate-shaped particles having an average aspect ratio of 3 or higher;
a penetration strength of the insulating layer in a thickness direction perpendicular to the surface of the positive electrode collector is 0.05 N/mm 2 or higher; and
the basis weight of the insulating layer is 0.5 mg/cm 2 or more.

2. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the inorganic filler is at least one selected from the group consisting of boehmite powder, zeolite powder, and alumina powder.

3. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, in the insulating layer, the proportion of the binder relative to the total of the inorganic filler and the binder is lower than 30 mass %.

4. The nonaqueous electrolyte secondary battery according to claim 1 , wherein the average thickness of the insulating later is 10 μm or less.

5. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the average thickness of the insulating layer is smaller than 10 μm.

6. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the average thickness of the insulating layer is 5 μm or less.

7. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the basis weight of the insulating layer is in the range of from 0.5 mg/cm 2 to 1.5 mg/cm 2 .

8. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the basis weight of the insulating layer is 1 mg/cm 2 or more.

9. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, in the insulating layer, the proportion of the binder relative to the total of the inorganic filler and the binder is equal to or lower than 20 mass %.

10. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, in the insulating layer, the proportion of the binder relative to the total of the inorganic filler and the binder is equal to or lower than 15 mass %.

11. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the positive electrode active material layer contains a positive electrode active material, where D 1 denotes the average particle size of the inorganic filler, D 3 denotes the average particle size of the positive electrode active material, the D 1 and the D 3 satisfies D 1 <D 3 .

12. The nonaqueous electrolyte secondary battery according to claim 1 , wherein, the insulating layer contains Li 3 PO4 (LPO).

13. The nonaqueous electrolyte secondary battery according to claim 12 , wherein, where D 1 denotes the average particle size of the inorganic filler, D 2 denotes the average particle size of the LPO in the insulating layer, the D 1 and the D 2 satisfies D 1 <D 2 .

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamada Takanobu
• Kaneko Tetsuya

Classifications

• H01G11/06

  with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC] · CPC title

• H01M10/6551

  Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/13

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

• H01G11/26

  characterised by their structure, e.g. multi-layered, porosity or surface features · CPC title