Titanium oxide particles, titanium oxide particle production method, power storage device electrode including titanium oxide particles, and power storage device provided with electrode including titanium oxide particles

Patent metadata

Field	Value
Publication number	US-2018072584-A1
Application number	US-201515558169-A
Country	US
Kind code	A1
Filing date	May 27, 2015
Priority date	Mar 31, 2015
Publication date	Mar 15, 2018
Grant date	—

Abstract

Provided are novel titanium oxide particles, production method thereof, and applications which do not need a conductive aid or minimize the conductive aid. Novel titanium oxide particles 1 employ a three-dimensional network structure in which multiple crystallites 2 are coupled in sequence, and a magneli phase 2 a is formed on the surface of the crystallites 2. The crystallites 2 are oriented at random, coupled with each other via pinacoid or end surface, and laminated as the three-dimensional network structure. A large number of spaces 3 in nano size is present in the titanium oxide particles 1, a grain boundary of the bonding interface is eliminated between the crystallites 2, while a large number of pores is present.

First claim

1 . A titanium oxide particles comprising:
a three-dimensional network structure having crystallites of titanium oxide coupled in sequence, wherein a magneli phase is formed on surfaces of the crystallites.

2 . The titanium oxide particles according to claim 1 , wherein the titanium oxide is lithium titanate represented by a general formula of Li α Ti β O γ .

3 . The titanium oxide particles according to claim 2 , wherein the titanium oxide is spinel type lithium titanate represented by Li 4 Ti 5 O 12 .

4 . The titanium oxide particles according to claim 1 , wherein the magneli phase is a titanium oxide represented by a general formula of Ti n O 2n−1 , where 3≦n≦10.

5 . The titanium oxide particles according to claim 4 , wherein the magneli phase is Ti 4 O 7 .

6 . The titanium oxide particles according to claim 1 , wherein the sequence of crystallites forms an electron path including the magneli phase.

7 . The titanium oxide particles according to claim 1 , wherein a plurality of spaces is formed in the three-dimensional network structure.

8 . The titanium oxide particles according to claim 7 , wherein a plurality of pores in communication with an interior of the three-dimensional network structure is formed between the crystallites.

9 . The titanium oxide particles according to claim 8 , wherein an ion path in communication with the spaces from the pore is formed.

10 . The titanium oxide particles according to claim 1 , wherein the crystallites are coupled with each other without a grain boundary.

11 . The titanium oxide particles according to claim 1 , wherein carbon is less than 5 wt % including zero relative to the whole particles.

12 . The titanium oxide particles according to claim 1 , wherein:
the crystallite is in a flat plate shape; and the three-dimensional network structure is a card house structure.

13 . The titanium oxide particles according to claim 1 , wherein the magneli phase is formed on an edge surface of the crystallites.

14 . An electrode for a power storage device comprising the titanium oxide particles according to claim 1 .

15 . A power storage device comprising an electrode that comprises the titanium oxide particles according to claim 1 .

16 . A production method of titanium oxide particles comprising:
burning out carbon by performing a heating process on a complex of crystallites of a titanium oxide with the carbon under an oxygen atmosphere to cause the crystallites of the titanium oxide to be in sequence, thereby forming particles employing a three-dimensional network structure, and also forming a magneli phase on a surface of the crystallites.

17 . The titanium oxide particle production method according to claim 16 , wherein a temperature of the heating process is 400 to 600° C.

18 . The titanium oxide particle production method according to claim 16 , wherein a time of the heating process is equal to or longer than 0.5 and equal to or shorter than 10 hours.

19 . The titanium oxide particle production method according to claim 16 , wherein the complex is produced by:
a mixing process of a source of the titanium oxide with a carbon source; and a process of heating a mixture having undergone the mixing process under an inert atmosphere.

20 . The titanium oxide particle production method according to claim 19 , wherein a temperature of the heating process under the inert atmosphere is 600 to 950° C.

21 . (canceled)

Assignees

• Nippon Chemicon

Inventors

• Naoi Katsuhiko
• Naoi Wako
• Tsumeda Satoru
• Ishimoto Shuichi
• Tamamitsu Kenji

Classifications

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• C01P2004/04

  obtained by TEM, STEM, STM or AFM · CPC title

• C01P2006/16

  Pore diameter · CPC title

• C01G23/005 Primary

  Alkali titanates · CPC title

• H01M4/1391

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