Lithium titanate powder, active material, and energy storage device using the same

Patent metadata

Field	Value
Publication number	US-9771273-B2
Application number	US-201414915532-A
Country	US
Kind code	B2
Filing date	Aug 29, 2014
Priority date	Aug 30, 2013
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

Provided is a lithium titanate powder for an electrode of an energy storage device, the lithium titanate powder comprising Li 4 Ti 5 O 12 as a main component, wherein, when the volume surface diameter calculated from the specific surface area determined by the BET method is represented as D BET and the crystallite diameter calculated from the half-peak width of the peak of the (111) plane of Li 4 Ti 5 O 12 by the Scherrer equation is represented as D X , D BET is 0.1 to 0.6 μm, D X is greater than 80 nm, and (D BET /D X (μm/μm)) the ratio of D BET to D X is 3 or less. Also provided are an active material including the lithium titanate powder and an energy storage device using the active material.

First claim

What is claimed is:

1. A lithium titanate powder comprising Li 4 Ti 5 O 12 as a main component, wherein,
when a volume surface diameter calculated from a specific surface area determined by a BET method is represented as D BET , and when a crystallite diameter calculated from a half-peak width of a peak for a (111) plane of Li 4 Ti 5 O 12 by a Scherrer equation is represented as D X , D BET is 0.1 to 0.6 μm, D X is larger than 80 nm, a D BET /D X (μm/μm) ratio of D BET to D X is 3 or less, and
a peak of Li 2 TiO 3 is not detected by X-ray diffraction.

2. The lithium titanate powder according to claim 1 , wherein D BET /D X (μm/μm), the ratio of D BET to D X is 2 or less.

3. The lithium titanate powder according to claim 1 , wherein D X is 500 nm or less.

4. The lithium titanate powder according to claim 1 , further comprising M, wherein M is at least one type of metal element selected from the group consisting of a group 2 element, a group 12 element, and a group 13 element.

5. The lithium titanate powder according to claim 4 , wherein the M is at least one type of metal element selected from the group consisting of Mg, Zn, Al, Ga, and In.

6. The lithium titanate powder according to claim 4 , wherein T M /T Ti , an atomic ratio of the M to Ti, for the entire lithium titanate powder measured by the inductively coupled plasma emission spectrometric analysis method is 0.001 to 0.05.

7. The lithium titanate powder according to claim 4 , wherein, in a cross-sectional analysis of a lithium titanate particle using a scanning transmission electron microscope, when an element concentration of the M measured by an energy dispersive X-ray spectroscopy at a 5 nm inner position from a surface of the lithium titanate particle along a straight line drawn vertically to a tangent of the lithium titanate particle surface is D1 (atm %) and when an element concentration of the M measured by an energy dispersive X-ray spectroscopy at a 100 nm inner position from the lithium titanate particle surface along the straight line is D2 (atm %), the D1 and D2 satisfy a formula (I)
D 1> D 2  (I).

8. The lithium titanate powder according to claim 4 , further comprising a fluorine element.

9. The lithium titanate powder according to claim 4 , suitable for use in an electrode of an energy storage device.

10. An active material comprising the lithium titanate powder according to claim 4 .

11. An energy storage device comprising the active material according to claim 10 .

12. A lithium-ion secondary battery comprising the active material according to claim 10 .

13. A hybrid capacitor comprising the active material according to claim 10 .

14. The lithium titanate powder according to claim 1 , further comprising fluorine.

15. The lithium titanate powder according to claim 1 , suitable for use in an electrode of an energy storage device.

16. An active material comprising the lithium titanate powder according to claim 1 .

17. An energy storage device comprising the active material according to claim 16 .

18. A lithium-ion secondary battery comprising the active material according to claim 16 .

19. A hybrid capacitor comprising the active material according to claim 16 .

20. A lithium titanate powder comprising Li 4 Ti 5 O 12 as a main component, wherein,
when a volume surface diameter calculated from a specific surface area determined by a BET method is represented as D BET , and when a crystallite diameter calculated from a half-peak width of a peak for a (111) plane of Li 4 Ti 5 O 12 by a Scherrer equation is represented as D X , D BET is 0.1 to 0.6 μm, D X is larger than 80 nm, and a D BET /D X (μm/μm) ratio of D BET to D X is 3 or less,
the lithium titanate powder further comprises M wherein M is at least one type of metal element selected from the group consisting of a group 2 element, a group 12 element, and a group 13 element, and
in a cross-sectional analysis of a lithium titanate particle using a scanning transmission electron microscope, when an element concentration of the M measured by an energy dispersive X-ray spectroscopy at a 5 nm inner position from a surface of the lithium titanate particle along a straight line drawn vertically to a tangent of the lithium titanate particle surface is D1 (atm %) and when an element concentration of the M measured by an energy dispersive X-ray spectroscopy at a 100 nm inner position from the lithium titanate particle surface along the straight line is D2 (atm %), a ratio D1/D2 of the D1 to the D2 satisfies a formula (II)
D 1/ D 2≧5  (II).

Assignees

• Ube Industries

Inventors

• Takemoto Hirofumi
• Tanaka Yoshizumi
• Fujino Hiroshi
• Iwamoto Yasumasa

Classifications

• C01P2004/03

  obtained by SEM · CPC title

• C01P2002/32

  spinel-type (AB2O4) · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/46

  Metal oxides · CPC title

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title