Lithium titanate particles and process for producing the lithium titanate particles, Mg-containing lithium titanate particles and process for producing the Mg-containing lithium titanate particles, negative electrode active substance particles for non-aqueous electrolyte secondary batteries, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-9293235-B2
Application number	US-201113819068-A
Country	US
Kind code	B2
Filing date	Aug 29, 2011
Priority date	Aug 31, 2010
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

According to the present invention, there are provided lithium titanate particles which exhibit an excellent initial discharge capacity and an enhanced high-efficiency discharge capacity retention rate as an active substance for non-aqueous electrolyte secondary batteries and a process for producing the lithium titanate particles, and Mg-containing lithium titanate particles.

First claim

The invention claimed is:

1. Lithium titanate particles with a spinel structure comprising TiO 2 in an amount of not more than 1.5 mass %, Li 2 TiO 3 in an amount of not less than 1 mass % and not more than 6 mass %, and Li 4 Ti 5 O 12 in an amount of not less than 94 mass % and not more than 99 mass % as determined according to a Rietveld analysis when indexed with Fd-3 m by XRD, and having a specific surface area of 7 to 15 m 2 /g as measured by BET method and a crystallite size of 80 to 200 nm.

2. The lithium titanate particles according to claim 1 , wherein a ratio (molar ratio) of Li to Ti (Li/Ti) in the particles is 0.805 to 0.83.

3. A process for producing the lithium titanate particles as defined in claim 1 , comprising the step of calcining a mixture comprising at least Li 2 TiO 3 and TiO 2 at a temperature of not lower than 650° C. and lower than 800° C.

4. Negative electrode active substance particles comprising the lithium titanate particles as defined in claim 1 .

5. The negative electrode active substance particles for non-aqueous electrolyte secondary batteries, wherein in a cell comprising the negative electrode active substance particles as defined in claim 4 and metallic lithium as a counter electrode, when a charging direction of the cell is the direction in which lithium is released, an initial discharge capacity of the cell is not less than 165 mAh/g, and an output characteristic of the cell as a discharge capacity ratio between 10 C and 0.1 C assuming that a C-rate upon measurement of the initial discharge capacity is 0.1 C is not less than 80%.

6. A non-aqueous electrolyte secondary battery comprising the negative electrode active substance particles as defined in claim 4 .

Assignees

• Yamamoto Akinori
• Okita Tomoko
• Yamamoto Hiroshi
• Mori Kohji
• Koga Kazumichi
• Kajiyama Akihisa
• Toda Kogyo Corp

Inventors

• Yamamoto Akinori
• Okita Tomoko
• Yamamoto Hiroshi
• Mori Kohji
• Koga Kazumichi
• Kajiyama Akihisa

Classifications

• H01B1/08 Primary

  oxides · CPC title

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title

• Y02E60/122

  Cross-Sectional Technologies · mapped topic

• C01P2004/03

  obtained by SEM · CPC title

• H01M10/0525

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