Positive electrode active material for lithium ion secondary battery, positive electrode for lithium ion secondary battery, and lithium ion secondary battery using same

Patent metadata

Field	Value
Publication number	US-2016285103-A1
Application number	US-201615077151-A
Country	US
Kind code	A1
Filing date	Mar 22, 2016
Priority date	Mar 27, 2015
Publication date	Sep 29, 2016
Grant date	—

Abstract

A positive electrode active material for lithium ion secondary battery, includes: a lithium nickel complex oxide represented by composition formula (1); a phosphate compound; and a coating layer formed on at least a part of a surface of a particle of the lithium nickel complex oxide, and including a high thermal conductive material with heat conductivity of 500 W/m·K or more. The coating layer of the particle of the lithium nickel complex oxide includes a portion connected to the coating layer of another particle of the lithium nickel complex oxide:
Li x Ni 1-y M y O 2   (1)

where M includes at least one metal selected from the group consisting of Co, Fe, Ti, Cr, Mg, Al, Cu, Ga, Mn, Zn, Sn, B, V, Ca, and Sr, and x and y are such that 0.05≦x≦1.2 and 0≦y≦0.5.

First claim

What is claimed is:

1 . A positive electrode active material for lithium ion secondary battery, comprising:
a lithium nickel complex oxide represented by composition formula (1); a phosphate compound; and a coating layer formed on at least a part of a surface of a particle of the lithium nickel complex oxide, and including a high thermal conductive material with heat conductivity of 500 W/m·K or more, wherein the coating layer of the particle of the lithium nickel complex oxide includes a portion connected to the coating layer of another particle of the lithium nickel complex oxide:
Li x Ni 1-y M y O 2   (1)

where M includes at least one metal selected from the group consisting of Co, Fe, Ti, Cr, Mg, Al, Cu, Ga, Mn, Zn, Sn, B, V, Ca, and Sr, and x and y are such that 0.05≦x≦1.2 and 0≦y≦0.5.

2 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the coating layer of the particle of the lithium nickel complex oxide includes a portion directly connected to the coating layer of the other particle of the lithium nickel complex oxide.

3 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the coating layer of the particle of the lithium nickel complex oxide includes a portion connected to the coating layer of the other particle of the lithium nickel complex oxide via flakes or bars of high thermal conductive material with heat conductivity of 500 W/m·K or more.

4 . The positive electrode active material for lithium ion secondary battery according to claim 2 , wherein
the coating layer of the particle of the lithium nickel complex oxide includes a portion connected to the coating layer of the other particle of the lithium nickel complex oxide via flakes or bars of high thermal conductive material with heat conductivity of 500 W/m·K or more.

5 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
a ratio of the phosphate compound to a total mass of the positive electrode active material for lithium ion secondary battery is 1 mass % to 40 mass %.

6 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the coating layer has an average thickness of 10 nm to 500 nm.

7 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the high thermal conductive material in the coating layer includes graphene or multi-layer graphene.

8 . The positive electrode active material for lithium ion secondary battery according to claim 3 , wherein
the flakes or bars of high thermal conductive material include graphene or multi-layer graphene.

9 . The positive electrode active material for lithium ion secondary battery according to claim 8 , wherein
the flakes or bars of high thermal conductive material include flakes of the multi-layer graphene.

10 . The positive electrode active material for lithium ion secondary battery according to claim 8 , wherein
the multi-layer graphene has an average thickness of 3 am to 100 nm.

11 . The positive electrode active material for lithium ion secondary battery according to claim 9 , wherein
the multi-layer graphene has an average thickness of 3 nm to 100 nm.

12 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the phosphate compound is a compound represented by composition formula (2), (3), or (4):
Li 3 V 2 (PO 4 ) 3   (2)

LiNPO 4   (3)

Li x NPO 4   (4)

where N is at least one selected from the group consisting of Mn, Co, Ni, Fe, and VO, and x is a value such that 1<x≦1.5.

13 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the phosphate compound is lithium vanadium phosphate represented by LiVOPO 4 or Li 3 V 2 (PO 4 ) 3 .

14 . The positive electrode active material for lithium ion secondary battery according to claim 1 , wherein
the lithium nickel complex oxide is a complex oxide represented by composition formula (5):
Li x Ni 1-y-z Co y Al z O 2   (5)

where x, y, and z are such that 0.05≦x≦1.2, 0<y≦0.5, 0<z≦0.5, and y+z≦0.5.

15 . A positive electrode for lithium ion secondary battery, comprising
the positive electrode active material for lithium ion secondary battery according to claim 1 .

16 . A lithium ion secondary battery comprising:
the positive electrode according to claim 15 ; a negative electrode including a negative electrode active material; a separator disposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte.

Assignees

• Tdk Corp

Inventors

• SHITABA Junpei
• Seki Hideaki
• Nojima Akinobu
• Fujita Shin
• Saegusa Masahiro

Classifications

• H01M10/654

  located inside the innermost case of the cells, e.g. mandrels, electrodes or electrolytes · CPC title

• H01M4/5825 Primary

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/622

  being polymers · CPC title