Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11695115-B2
Application number	US-202017081310-A
Country	US
Kind code	B2
Filing date	Oct 27, 2020
Priority date	Oct 30, 2019
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

A positive electrode active material for a non-aqueous electrolyte secondary battery according to a configuration includes a lithium-transition metal composite oxide containing nickel (Ni) in an amount of greater than or equal to 80 mol %, in which boron (B) is present at least on a particle surface of the lithium-transition metal composite oxide. In the lithium-transition metal composite oxide, when particles having a larger particle size than a volume-based 70% particle size (D70) are first particles and particles having a smaller particle size than a volume-based 30% particle size (D30) are second particles, a coverage ratio of B on surfaces of the second particle is larger than a coverage ratio of B on surfaces of the first particle by 5% or greater.

First claim

The invention claimed is:

1. A positive electrode active material for a non-aqueous electrolyte secondary battery, comprising:
a lithium-transition metal composite oxide containing nickel (Ni) in an amount of greater than or equal to 80 mol % with respect to a total number of moles of metal elements other than lithium (Li), wherein boron (B) is present at least on a particle surface of the lithium-transition metal composite oxide, wherein
the lithium-transition metal composite oxide is a secondary particle formed by flocculation of a plurality of primary particles;
the secondary particle comprises a plurality of secondary particles wherein those having a larger particle size than a volume-based 70% particle size (D70) are defined as first particles, those having a smaller particle size than a volume-based 30% particle size (D30) are defined as second particles;
a coverage ratio of B on surfaces of the second particles is larger than a coverage ratio of B on surfaces of the first particles by 5% or greater, the coverage ratio being a ratio of an area of surfaces on which B is present to a total area of surfaces of each of the secondary particles.

2. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein
the lithium-transition metal composite oxide is a composite oxide represented by a general formula Li a Ni b Co c Mn d Me e B f O g (in the formula, 0.8≤a≤1.2, b≥0.80, c≤0.10, 0.03≤d≤0.12, 0≤e≤0.05, 0.001≤f≤0.020, 1≤g≤2, b+c+d+e+f=1, and Me is at least one metal element selected from elements of groups 4 to 6).

3. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein
B is present on the surfaces of the first particle and the second particle in a form of a boron compound containing Li and B.

4. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein
the coverage ratio of B on the surfaces of the second particles is 80% ˜98%.

5. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein
the coverage ratio of B on the surfaces of the first particle is 50% ˜80%.

6. The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1 , wherein
a molar fraction of B with respect to a total number of moles of metal elements other than Li in the second particle is larger than a molar fraction of boron with respect to a total number of moles of metal elements other than Li in the first particle.

7. A non-aqueous electrolyte secondary battery comprising:
a positive electrode having the positive electrode active material according to claim 1 ;
a negative electrode; and
a non-aqueous electrolyte.

Assignees

• Panasonic Corp
• Toyota Motor Co Ltd
• Panasonic Holdings Corp

Inventors

• Goto Natsumi
• Ko Takashi
• Suzuki Shinya
• Niina Fumiharu
• Tsuruta Sho
• Hanazaki Ryo

Classifications

• H01M4/364

  as mixtures · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M10/0525

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