Cathode active material for lithium battery, lithium battery, and method for producing cathode active material for lithium battery

Patent metadata

Field	Value
Publication number	US-2016043395-A1
Application number	US-201514817956-A
Country	US
Kind code	A1
Filing date	Aug 4, 2015
Priority date	Aug 8, 2014
Publication date	Feb 11, 2016
Grant date	—

Abstract

The main object of the present invention is to provide a cathode active material for a lithium battery capable of inhibiting resistance from increasing with time. The present invention attains the object by providing a cathode active material for a lithium battery comprising: a cathode active material containing an Mn element and being an oxide; and a coating portion formed on a surface of the cathode active material, characterized in that the coating portion contains a Li element, a P element, an O element and the Mn element derived from the cathode active material, and a ratio of the Mn element to the P element, (Mn/P) is 1 or more at an interface between the cathode active material and the coating portion.

First claim

What is claimed is:

1 . A cathode active material for a lithium battery comprising:
a cathode active material comprising an Mn element and being an oxide; and a coating portion formed on a surface of the cathode active material, wherein the coating portion comprises a Li element, a P element, an O element and the Mn element derived from the cathode active material, and a ratio of the Mn element to the P element, (Mn/P) is 1 or more at an interface between the cathode active material and the coating portion.

2 . The cathode active material for a lithium battery according to claim 1 , wherein when a location in which a number of atoms of the P element (%) becomes maximum in a thickness direction of the coating portion is regarded as B, the Mn/P in the location B is 0.79 or more.

3 . A lithium battery comprising a cathode active material layer, an anode active material layer, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer,
wherein the cathode active material layer comprises the cathode active material for a lithium battery according to claim 1 , and at least one of the cathode active material layer and the solid electrolyte layer comprises a sulfide solid electrolyte material.

4 . A lithium battery comprising a cathode active material layer, an anode active material layer, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer,
wherein the cathode active material layer comprises the cathode active material for a lithium battery according to claim 2 , and at least one of the cathode active material layer and the solid electrolyte layer comprises a sulfide solid electrolyte material.

5 . A method for producing a cathode active material for a lithium battery, the cathode active material for a lithium battery comprising a cathode active material comprising an Mn element and being an oxide, and a coating portion,
the method comprising a step of forming the coating portion on a surface of the cathode active material by using a sputtering method, wherein the coating portion comprises a Li element, a P element, an O element and the Mn element derived from the cathode active material, and a ratio of the Mn element to the P element, (Mn/P) is 1 or more at an interface between the cathode active material and the coating portion.

6 . The method for producing a cathode active material for a lithium battery according to claim 5 , wherein when a location in which a number of atoms of the P element (%) becomes maximum in a thickness direction of the coating portion is regarded as B, the Mn/P in the location B is 0.79 or more.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kawakami Masatsugu
• Ohtomo Takamasa
• Kato Yuki
• Yamasaki Hisatsugu

Classifications

• C23C14/34

  Sputtering · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M10/0525

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

• H01M4/505 Primary

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