Active material, electrode, lithium ion secondary battery, and method for manufacturing active material

Patent metadata

Field	Value
Publication number	US-9564641-B2
Application number	US-201214005385-A
Country	US
Kind code	B2
Filing date	Mar 30, 2012
Priority date	Mar 31, 2011
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

An active material that can achieve sufficient discharge capacity at high discharging rate, an electrode including the active material, and a lithium ion secondary battery including the electrode, and a method for manufacturing the active material are provided. The active material includes a LiVOPO 4 powder, a first carbon powder, and a second carbon powder. A relational expression of 0.05≦A1/A2≦0.5 is satisfied, where A1 represents the ratio of the G band peak height observed around 1580 cm −1 in Raman spectrum of the first carbon powder to the 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the first carbon powder, and A2 represents the ratio of the G band peak height observed around 1580 cm −1 in Raman spectrum of the second carbon powder to the 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the second carbon powder.

First claim

The invention claimed is:

1. An active material comprising:
a LiVOPO 4 powder;
a first carbon powder; and
a second carbon powder,
wherein:
a relational expression of 0.05≦A1/A2≦0.5 is satisfied, where A1 represents a ratio of a G band peak height observed around 1580 cm −1 in Raman spectrum of the first carbon powder to a 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the first carbon powder, and A2 represents a ratio of a G band peak height observed around 1580 cm −1 in Raman spectrum of the second carbon powder to a 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the second carbon powder;
A1 for the first carbon powder is 2.00, 2.19, or 1.60; and
A2 for the second carbon powder is 13.89 or 14.41.

2. The active material according to claim 1 , wherein a relational expression of 0.1≦A1/A2≦0.2 is satisfied.

3. The active material according to claim 2 , wherein a relational expression of 0.02≦M1≦0.98 is satisfied, where M1 represents a ratio of weight of the first carbon powder to total weight of the first carbon powder and the second carbon powder.

4. The active material according to claim 1 , wherein a relational expression of 0.02≦M1≦0.98 is satisfied, where M1 represents a ratio of weight of the first carbon powder to total weight of the first carbon powder and the second carbon powder.

5. The active material according to claim 1 , wherein a relational expression of 0.03≦M2≦0.2 is satisfied, where M2 represents a ratio of weight of the first carbon powder and the second carbon powder to total weight of the LiVOPO 4 powder, the first carbon powder, and the second carbon powder.

6. The active material according to claim 1 , wherein the LiVOPO 4 powder is obtained by hydrothermal synthesis.

7. The active material according to claim 1 , wherein the LiVOPO 4 powder, the first carbon powder, and the second carbon powder are mixed by a planetary ball mill.

8. An electrode comprising the active material according to claim 1 .

9. A lithium ion secondary battery comprising the electrode according to claim 8 .

10. The active material according to claim 1 , wherein the first carbon powder and the second carbon powder have a mean particle diameter of 20 to 150 nm.

11. The active material according to claim 1 , wherein A1 for the first carbon powder is 2.00 or 2.19.

12. A method for manufacturing an active material, comprising:
mixing a LiVOPO 4 powder, a first carbon powder, and a second carbon powder,
wherein:
a relational expression of 0.05≦A1/A2≦0.5 is satisfied, where A1 represents a ratio of a G band peak height observed around 1580 cm −1 in Raman spectrum of the first carbon powder to a 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the first carbon powder, and A2 represents a ratio of a G band peak height observed around 1580 cm −1 in Raman spectrum of the second carbon powder to a 2D band peak height observed around 2700 cm −1 in the Raman spectrum of the second carbon powder;
A1 for the first carbon powder is 2.00, 2.19, or 1.60; and
A2 for the second carbon powder is 13.89 or 14.41.

13. The method according to claim 12 , wherein a relational expression of 0.1≦A1/A2≦0.2 is satisfied.

14. The method according to claim 13 , wherein, when a relational expression of A1<A2 is satisfied, a relational expression of 0.02≦M1≦0.98 is satisfied, where M1 represents a ratio of weight of the first carbon powder to total weight of the first carbon powder and the second carbon powder.

15. The method according to claim 12 , wherein, when a relational expression of A1<A2 is satisfied, a relational expression of 0.02≦M1≦0.98 is satisfied, where M1 represents a ratio of weight of the first carbon powder to total weight of the first carbon powder and the second carbon powder.

16. The method according to claim 12 , wherein a relational expression of 0.03≦M2≦0.2 is satisfied, where M2 represents a ratio of weight of the first carbon powder and the second carbon powder to total weight of the LiVOPO 4 powder, the first carbon powder, and the second carbon powder.

17. The method according to claim 12 , wherein the LiVOPO 4 powder is obtained by hydrothermal synthesis.

18. The method according to claim 12 , wherein the mixing is performed by a planetary ball mill.

Assignees

• Otsuki Keitaro
• Sano Atsushi
• Tdk Corp

Inventors

• Otsuki Keitaro
• Sano Atsushi

Classifications

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• H01M10/0525

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

• Y02P70/54

  Cross-Sectional Technologies · mapped topic

• H01M4/587

  for inserting or intercalating light metals · CPC title