Secondary battery, battery pack, and vehicle

Patent metadata

Field	Value
Publication number	US-10978752-B2
Application number	US-201816122126-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Mar 19, 2018
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

According to one embodiment, a secondary battery is provided. The secondary battery includes a negative electrode. The negative electrode includes an active material composite. The active material composite includes active material particles and a layer covering at least a portion of surfaces of the active material particles. The active material particles include titanium-containing oxide particles. The layer contains N and Si. The layer includes a first surface facing the at least the portion of surfaces of the active material particles and a second surface defining a layer thickness from the first surface. An N concentration in the layer decreases from the first surface to the second surface. A Si concentration in the layer increases from the first surface to the second surface.

First claim

The invention claimed is:

1. A secondary battery comprising:
a positive electrode;
a negative electrode comprising an active material composite; and
a nonaqueous electrolyte comprising a silyl group-containing compound comprising a trialkylsilyl group and/or a trialkoxysilyl group, wherein the active material composite comprises active material particles and a layer covering at least a portion of surfaces of the active material particles, and the active material particles comprising titanium-containing oxide particles,
the layer comprises N and Si and comprises a first surface facing the at least the portion of the surfaces of the active material particles and a second surface defining a layer thickness from the first surface,
a N concentration in the layer decreases from the first surface to the second surface,
a Si concentration in the layer increases from the first surface to the second surface, and
the nonaqueous electrolyte satisfies the following formulas (1) to (3):
0<B/A≤0.5 (1)
0 wt %<A≤2.0 wt % (2); and
0 wt %<B<0.01 wt % (3),
wherein A is a concentration [wt %] of the silyl group-containing compound in the nonaqueous electrolyte, and B is a concentration [wt %] of a diisocyanate compound in the nonaqueous electrolyte.

2. The secondary battery according to claim 1 , wherein 0.5 wt %≤A≤2.0 wt %.

3. The secondary battery according to claim 1 , wherein 0.5 wt %≤A≤2 wt %.

4. The secondary battery according to claim 1 , wherein the positive electrode comprises a composite oxide represented by the general formula Li x MO 2 , 0<x≤1 in the general formula, and M comprises at least one selected from the group consisting of Ni, Co and Mn.

5. The secondary battery according to claim 1 , wherein the titanium-containing oxide particles comprise at least one titanium-containing oxide selected from the group consisting of spinel type lithium-titanium composite oxide, monoclinic P-type titanium-containing oxide, monoclinic niobium titanium composite oxide, orthorhombic titanium-containing composite oxide, ramsdellite type lithium-titanium composite oxide, hollandite type lithium-titanium composite oxide, anatase type titanium-containing oxide, and rutile type titanium-containing oxide.

6. The secondary battery according to claim 1 , wherein the active material composite further comprises a carbon-containing layer interposed at least a portion between the active material particles and the layer.

7. The secondary battery according to claim 1 , wherein the silyl group-containing compound comprises at least one selected from the group consisting of trimethylsilyl phosphate, triethylsilyl phosphate, tris-trimethylsilyl phosphate, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane.

8. A battery pack comprising the secondary battery according to claim 1 .

9. The battery pack according to claim 8 , further comprising: an external power distribution terminal; and a protective circuit.

10. The battery pack according to claim 8 , comprising plural of the secondary battery, the secondary batteries being electrically connected in series, in parallel, or in a combination of in series and in parallel.

11. A vehicle comprising the battery pack according to claim 8 .

12. The vehicle according to claim 11 , wherein the battery pack comprises a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.

13. The secondary battery according to claim 1 , wherein the silyl group-containing compound comprises a trialkylsilyl group and a trialkoxysilyl group.

14. The secondary battery according to claim 1 , wherein the titanium-containing oxide particles are monoclinic niobium titanium composite oxide particles.

Assignees

• Toshiba Kk
• Toshiba Infrastructure Systems & Solutions Corp

Inventors

• Fukaya Taro
• Kishi Takashi
• Ise Kazuki
• Yoshima Kazuomi
• Yamashita Yasunobu
• Harada Yasuhiro
• Takami Norio

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/366

  as layered products · CPC title