Positive electrode material for lithium secondary battery and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-2017040601-A1
Application number	US-201615229484-A
Country	US
Kind code	A1
Filing date	Aug 5, 2016
Priority date	Aug 7, 2015
Publication date	Feb 9, 2017
Grant date	—

Abstract

Provided is a positive electrode material for a lithium secondary battery that excels in durability and has a high electron conductivity (typically, a low battery resistance). A positive electrode material for a lithium secondary battery, which is provided by the present invention, includes positive electrode active material particles that can reversibly store and release a charge carrier, and lithium phosphate. Each of the positive electrode active material particles has a hollow structure having a shell configured of primary particles and a hollow portion formed inside the shell. Lithium phosphate is disposed inside the hollow portion, and no lithium phosphate is disposed on the outer circumferential surface of each of the positive electrode active material particles.

First claim

What is claimed is:

1 . A positive electrode material for use in a lithium secondary battery, the positive electrode material comprising:
positive electrode active material particles that can reversibly store and release a charge carrier; and lithium phosphate, wherein each of the positive electrode active material particles has a hollow structure having a shell configured of primary particles and a hollow portion formed inside the shell, and lithium phosphate is disposed inside the hollow portion, and no lithium phosphate is disposed on an outer circumferential surface of each of the positive electrode active material particles.

2 . The positive electrode material according to claim 1 , wherein
lithium phosphate is included in the positive electrode material in an amount from 0.1 part by mass to 4 parts by mass per 100 parts by mass of the positive electrode active material particles.

3 . The positive electrode material according to claim 1 , wherein the positive electrode active material is a lithium transition metal oxide including at least nickel, cobalt, and manganese.

4 . A method for manufacturing the positive electrode material according to claim 1 , comprising:
preparing positive electrode active material particles that can reversibly store and release a charge carrier, each of the positive electrode active material particles having a hollow structure having a shell configured of primary particles and a hollow portion formed inside the shell; mixing the positive electrode active material particles with a reaction starting material of lithium phosphate; disposing the reaction starting material of lithium phosphate at least in hollow portions of the positive electrode active material particles by using moisture in the air or added moisture; and generating lithium phosphate from the reaction starting material of lithium phosphate disposed in the hollow portions of the positive electrode active material particles, and disposing lithium phosphate in the hollow portions of the positive electrode active material particles.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nakayama Tetsuri

Classifications

• 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

• H01M4/5825

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

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M2004/028

  Positive electrodes · CPC title