Secondary battery positive electrode, secondary battery positive electrode current collector, and secondary battery

Patent metadata

Field	Value
Publication number	US-2021013516-A1
Application number	US-201916977579-A
Country	US
Kind code	A1
Filing date	Jan 15, 2019
Priority date	Mar 9, 2018
Publication date	Jan 14, 2021
Grant date	—

Abstract

This positive electrode includes: a positive electrode current collector; a positive electrode mixed material layer that is formed on at least one surface of the positive electrode current collector; and a protective layer which includes an insulating inorganic compound and a conductive material, and is interposed between the positive electrode current collector and the positive electrode mixed material layer. The protective layer includes secondary particles comprising agglomerated primary particles of the inorganic compound. The median value of the particle size of the secondary particles is 30 μm or less.

First claim

1 . A positive electrode for a secondary battery comprising:
a positive electrode current collector, a positive electrode mixture layer formed on at least one side of the positive electrode current collector, and a protective layer including an insulating inorganic compound and a conductive agent, the protective layer being interposed between the positive electrode current collector and the positive electrode mixture layer, wherein the protective layer includes secondary particles formed by aggregation of primary particles of the inorganic compound, and a median value of a particle size of the secondary particles is 30 μm or less.

2 . The positive electrode for a secondary battery according to claim 1 , wherein a median value of the particle size of the secondary particles is 1 μm to 30 μm.

3 . The positive electrode for a secondary battery according to claim 1 , wherein a thickness of the protective layer is 0.5 μm to 50 μm.

4 . The positive electrode for a secondary battery according to claim 1 , wherein a particle size of the primary particles is 5 μm or less.

5 . The positive electrode for a secondary battery according to claim 1 , wherein a particle size of the secondary particles is 50 μm or less.

6 . The positive electrode for a secondary battery according to claim 1 , wherein a deviation of the particle size of the secondary particles is 10 μm or less.

7 . The positive electrode for a secondary battery according to claim 1 , wherein the protective layer satisfies at least one condition of (1) to (4) below:
(1) 20 to 45 secondary particles having a particle size of 5 μm to 15 μm are included, (2) 30 to 55 secondary particles having a particle size of 15 μm to 25 μm are included, (3) 5 to 25 secondary particles having a particle size of 25 μm to 35 μm are included, and (4) 1 to 15 secondary particles having a particle size of 35 μm to 45 μm are included, per unit area of 1 mm 2 of the positive electrode.

8 . A positive electrode current collector for a secondary battery, comprising a protective layer formed on a surface thereof, the protective layer including an insulating inorganic compound and a conductive agent, wherein
the protective layer includes secondary particles formed by aggregation of primary particles of the inorganic compound, and a median value of a particle size of the secondary particles is 30 μm or less.

9 . A secondary battery, comprising:
the positive electrode for a secondary battery according to claim 1 ; a negative electrode; and an electrolyte.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Saito Kohei
• Takahashi Takahiro
• Takezawa Hideharu
• Shiozaki Tomoki

Classifications

• H01M4/624

  Electric conductive fillers · CPC title

• H01M4/362

  Composites · CPC title

• H01M4/663

  containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M4/664

  Ceramic materials · CPC title