Lithium—manganese composite oxide, secondary battery, and electric device

Patent metadata

Field	Value
Publication number	US-9293236-B2
Application number	US-201414318727-A
Country	US
Kind code	B2
Filing date	Jun 30, 2014
Priority date	Jul 15, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

The amount of lithium ions that can be received and released in and from a positive electrode active material is increased, and high capacity and high energy density of a secondary battery are achieved. Provided is a lithium-manganese composite oxide represented by Li x Mn y M z O w , where M is a metal element other than Li and Mn, or Si or P, and y, z, and w satisfy 0≦x/(y+z)<2, y>0, z>0, 0.26≦(y+z)/w<0.5, and 0.2<z/y<1.2. The lithium manganese composite oxide has high structural stability and high capacity.

First claim

The invention claimed is:

1. A lithium-manganese composite oxide represented by Li x Mn y Ni z O w ,
wherein y, z and ware each greater than zero and satisfy 0.26≦(y+z)/w<0.5,
wherein the lithium-manganese composite oxide comprises a layered rock-salt crystal structure and a spinel crystal structure, and
wherein x is greater than or equal to zero, and x, y and z satisfy 1.4≦x/(y+z)≦1.64 and 0.2<z/y<1.2.

2. A lithium-ion secondary battery comprising the lithium-manganese composite oxide according to claim 1 as a positive electrode active material.

3. An electric device comprising the lithium-ion secondary battery according to claim 2 .

4. A lithium-manganese composite oxide represented by Li x Mn y Ni z O w ,
wherein x is greater than or equal to zero,
wherein y, z, and w are each greater than zero,
wherein x, y, z, and w satisfy 1.4≦x/(y+z)≦1.64, 0.26≦(y+z)/w<0.5 and 0.2<z/y<1.2,
wherein the lithium-manganese composite oxide comprises a layered rock-salt crystal structure and a spinel crystal structure,
wherein the layered rock-salt crystal structure belongs to a space group C12/m1, and
wherein the layered rock-salt crystal structure, the sum of A(Mn) 2b and A(Ni) 2b is greater than or equal to 40%,
wherein A(Mn) 2b is an occupancy of Mn at the 2b site, and
wherein A(Ni) 2b is an occupancy of Ni at the 2b site,
wherein in the layered rock-salt crystal structure, the sum of A(Mn) 2c+4h and A(Ni) 2c+4h is greater than or equal to 0.2%,
wherein A(Mn) 2c-4h is an occupancy of Mn at a 2c site and an occupancy of Mn at a 4h site, represented by Formula (1),
wherein A(Ni) 2c+4h is an occupancy of Ni at the 2c site and an occupancy of Ni at the 4h site, represented by Formula (2),
wherein A(Mn) 2c is the occupancy of Mn at the 2c site, A(Ni) 2c is the occupancy of Ni at the 2c site, A(Mn) 4h is the occupancy of Mn at the 4h site, and A(Ni) 4h is the occupancy of Ni at the 4h site,
A(Mn) 2c+4h =[A(Mn) 2c ×1+A(Mn) 4h ×2]÷(1+2)  Formula (1)

A(Ni) 2c+4h =[A(Ni) 2c ×1+A(Ni) 4h ×2]÷(1+2)  Formula (2).

5. A lithium-ion secondary battery comprising the lithium-manganese composite oxide according to claim 4 as a positive electrode active material.

6. An electric device comprising the lithium-ion secondary battery according to claim 5 .

7. A lithium-manganese composite oxide represented by Li x Mn y Ni z O w ,
wherein x is greater than or equal to zero,
wherein y, z, and w are each greater than zero,
wherein x, y, z, and w satisfy 1.4≦x/(y+z)≦1.64, 0.26≦(y+z)/w<0.5 and 0.2<z/y<1.2,
wherein the lithium-manganese composite oxide comprises a layered rock-salt crystal structure and a spinel crystal structure, and
wherein the layered rock-salt crystal structure belongs to a space group C12/m1, and
wherein in the layered rock-salt crystal structure, an a-axis lattice constant is larger than or equal to 0.494 nm and a b-axis lattice constant is larger than or equal to 0.856 nm.

8. The lithium-manganese composite oxide according to claim 7 , wherein a c-axis lattice constant of the layered rock-salt crystal structure is larger than or equal to 0.5021 nm.

9. A lithium-ion secondary battery comprising the lithium-manganese composite oxide according to claim 7 as a positive electrode active material.

10. An electric device comprising the lithium-ion secondary battery according to claim 9 .

Assignees

• Semiconductor Energy Lab
• Semidonconductor Energy Lab Co Ltd

Inventors

• Kawakami Takahiro
• Yoshitomi Shuhei
• Ochiai Teruaki
• Saito Yumiko
• Momma Yohei
• Seo Satoshi
• Mikami Mayumi
• Adachi Shunsuke

Classifications

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01B1/08 Primary

  oxides · CPC title

• H01M4/525

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

• H01M10/0525

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