Lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-11424444-B2
Application number	US-202016742099-A
Country	US
Kind code	B2
Filing date	Jan 14, 2020
Priority date	Jan 15, 2019
Publication date	Aug 23, 2022
Grant date	Aug 23, 2022

Abstract

A lithium ion secondary battery suppressed in heat generation entailed by charging and discharging is provided. A lithium ion secondary battery includes a positive electrode and a negative electrode. The positive electrode includes a positive electrode collector, a positive electrode active material layer provided at some part of the surface of the positive electrode collector, and including a positive electrode active material, and an insulation layer provided so as to be at the other part of the surface of the positive electrode collector and to be adjacent to the positive electrode active material layer. The insulation layer includes an inorganic filler, LPO, and a binder.

First claim

What is claimed is:

1. A lithium ion secondary battery comprising:
a positive electrode, the positive electrode comprising:
a positive electrode collector;
a positive electrode active material layer provided on a first region of a surface of the positive electrode collector including a positive electrode active material; and
an insulation layer provided on a second region of the surface of the positive electrode collector, and adjacent to the positive electrode active material layer; and

a negative electrode;
and
wherein the insulation layer includes an inorganic filler, trilithium phosphate, and a binder, and the proportion of the trilithium phosphate in the insulation layer is from 0.1 to 10 parts by mass with respect to 100 parts by mass of the inorganic filler.

2. The lithium ion secondary battery according to claim 1 ,
wherein the positive electrode active material layer includes trilithium phosphate, and
P1/P2≥1 is satisfied, where P1 represents the proportion of the trilithium phosphate occupying the insulation layer, and P2 represents the proportion of the trilithium phosphate occupying the positive electrode active material layer.

3. The lithium ion secondary battery according to claim 2 ,
wherein S1/S2 is 1 or more, where S1 represents the specific surface area of the trilithium phosphate included in the insulation layer, and S2 represents the proportion of the trilithium phosphate included in the positive electrode active material layer.

4. The lithium ion secondary battery according to claim 1 ,
wherein D1<D2<D3 is satisfied, where D1 represents the average particle diameter of the inorganic filler included in the insulation layer, D2 represents the average particle diameter of the trilithium phosphate included in the insulation layer, and D3 represents the average particle diameter of the positive electrode active material included in the positive electrode active material layer.

5. The lithium ion secondary battery according to claim 1 ,
wherein T1/T2≤1 is satisfied, where T1 represents the average thickness of the insulation layer, and T2 represents the average thickness of the positive electrode active material layer.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamada Takanobu
• Kato Masaki

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/62

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

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M10/0525 Primary

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