Positive electrode material for secondary battery, method for manufacturing the same, and lithium-ion secondary battery

Patent metadata

Field	Value
Publication number	US-10903493-B2
Application number	US-201815880593-A
Country	US
Kind code	B2
Filing date	Jan 26, 2018
Priority date	Feb 1, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A positive electrode material for a secondary battery, wherein the positive electrode material includes a triclinic crystal structure and is represented by Li4+x(Fe1−zMz)4−0.5x(P2O7)3, where −0.65≤x≤0.75, 0.0<z≤0.7, and M represents a divalent metal other than Fe.

First claim

What is claimed is:

1. A positive electrode material for a secondary battery,
wherein the positive electrode material includes a triclinic crystal structure and is represented by Li 4+x (Fe 1−z Mg z ) 4−0.5x (P 2 O 7 ) 3 , where −0.65≤x≤0.75, 0.0<z≤0.7.

2. The positive electrode material according to claim 1 ,
wherein the crystal structure belongs to Space group P-1.

3. A lithium-ion secondary battery comprising:
a positive electrode including the positive electrode material for a secondary battery;
a negative electrode; and
an electrolyte,
wherein the positive electrode material includes a triclinic crystal structure and is represented by Li 4+x (Fe 1−z Mg z ) 4−0.5x (P 2 O 7 ), where −0.65≤x≤0.75, 0.0<z≤0.7.

4. The lithium-ion secondary battery according to claim 3 ,
wherein the crystal structure belongs to Space group P-1.

5. A method for manufacturing a positive electrode material for a secondary battery, the method comprising:
generating a mixture by mixing a lithium source, an iron source, a magnesium source, and a phosphate source with one another; and
performing a heat treatment on the mixture to acquire a positive electrode material for secondary batteries which includes a triclinic crystal structure and is represented Li 4+x (Fe 1−z Mg z ) 4−0.5x (P 2 O 7 ) 3 , where −0.65≤x≤0.75, 0.0<z≤0.7.

6. The method according to claim 5 ,
wherein the heat treatment is performed at 470° C. or more and 720° C. or less.

7. The method according to claim 5 ,
wherein the heat treatment is performed in an inert atmosphere.

Assignees

• Fujitsu Ltd

Inventors

• Kurita Tomochika
• Iwata Jiyunichi

Classifications

• C01B25/42

  Pyrophosphates · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2004/028

  Positive electrodes · 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

• H01M4/5825 Primary

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