Positive electrode active material and nonaqueous electrolyte secondary battery using the positive electrode active material

Patent metadata

Field	Value
Publication number	US-12401017-B2
Application number	US-202117564224-A
Country	US
Kind code	B2
Filing date	Dec 29, 2021
Priority date	Jan 5, 2021
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

The present disclosure provides a positive electrode active material capable of imparting a nonaqueous electrolyte secondary battery with excellent output characteristic and cycle characteristic. The positive electrode active material herein disclosed includes a core part including a lithium composite oxide, a first region formed on at least a partial surface of the core part, and including tungsten (W), and a second region formed on at least a partial surface of the first region, and including titanium (Ti). The W concentration of the first region with TEM-EDX analysis is higher than the W concentration of the core part.

First claim

What is claimed is:

1. A positive electrode active material for use in a nonaqueous electrolyte secondary battery,
the positive electrode active material, comprising:
a core part including a lithium composite oxide;
a first region formed on at least a partial surface of the core part, and including tungsten (W); and
a second region formed on at least a partial surface of the first region, and including titanium (Ti), wherein the second region comprises a different material from the first region,
wherein a W concentration of the first region with TEM-EDX analysis is higher than a W concentration of the core part, and
the second region is configured such that an atomic ratio (Ti/W) of Ti to W in the overall positive electrode active material is 0.2 or more and 0.9 or less.

2. The positive electrode active material according to claim 1 ,
wherein the second region includes TiO 2 and/or a composite oxide including Li and Ti as titanium-containing compounds.

3. The positive electrode active material according to claim 2 ,
wherein the second region includes TiO 2 as the titanium-containing compound, and a Ti concentration of TiO 2 identified as brookite type TiO 2 based on Ti peak analysis of XAFS with a Ti concentration of the titanium-containing compound taken as 100 mol % is 10 mol % or more.

4. A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein
the positive electrode includes the positive electrode active material according to claim 1 .

5. The positive electrode active material according to claim 1 ,
wherein the first region is formed on an entire surface of the core part.

6. The positive electrode active material according to claim 1 , wherein a thickness of the first region ranges from 10 nanometers (nm) to 100 nm.

7. The positive electrode active material according to claim 1 , wherein the second region is interspersed on the at least partial surface of the first region, and the second region partially coats the first region.

8. The positive electrode active material according to claim 1 , wherein the second region is configured such that the atomic ratio Ti/W in the overall positive electrode active material is 0.6 or more and 3.5 or less.

9. The positive electrode active material according to claim 1 , wherein the second region includes a composite oxide including Li and Ti as titanium-containing compounds.

10. The positive electrode active material according to claim 1 , wherein the second region includes TiO 2 and a composite oxide including Li and Ti as titanium-containing compounds.

11. A positive electrode active material for use in a nonaqueous electrolyte secondary battery,
the positive electrode active material, comprising:
a core part including a lithium composite oxide;
a first region formed on at least a partial surface of the core part, and including tungsten (W); and
a second region formed on at least a partial surface of the first region, and including titanium (Ti), wherein the second region comprises a different material from the first region,
wherein a W concentration of the first region with TEM-EDX analysis is higher than a W concentration of the core part, and

the second region is configured such that an atomic ratio (Ti/W) of Ti to W in the overall positive electrode active material is 3.5 or more to 9 or less.

Assignees

• Prime Planet Energy & Solutions Inc

Inventors

• Procter Momoko

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M10/0525

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

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title