Nonaqueous electrolyte battery

Patent metadata

Field	Value
Publication number	US-10355273-B2
Application number	US-201715449443-A
Country	US
Kind code	B2
Filing date	Mar 3, 2017
Priority date	Sep 10, 2014
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

According to an embodiment, a nonaqueous electrolyte battery is provided. The nonaqueous electrolyte includes a negative electrode, a positive electrode and a nonaqueous electrolyte. The negative electrode includes negative electrode active material particles. The negative electrode active material particles include a spinel-type lithium titanate. The negative electrode has such a surface state that a ratio ALi/ATi of an Li atom abundance ratio ALi to a Ti atom abundance ratio ATi, according to a photoelectron spectroscopic measurement for a surface, is increased at a rate of 0.002 to 0.02 per cycle in a charge-and-discharge cycle test under the predetermined condition.

First claim

What is claimed is:

1. A nonaqueous electrolyte battery comprising:
a negative electrode comprising negative electrode active material particles comprising a spinel-type lithium titanate, the negative electrode having such a surface state that a ratio A Li /A Ti of an Li atom abundance ratio A Li to a Ti atom abundance ratio A Ti , obtained according to a photoelectron spectroscopic measurement for a surface, is increased at a rate of 0.002 to 0.02 per cycle in a charge-and-discharge cycle test, wherein the test is performed in a 45° C. environment at 2 C rate within a voltage range from a lower limit battery voltage of 1.5±0.1 V to a upper limit battery voltage of 2.7±0.1 V, the Li atom abundance ratio A Li is calculated from a peak derived from a Li 1s-orbital that appears in a binding energy region of 52 eV to 58 eV, and the Ti atom abundance ratio A Ti is calculated from a peak derived from a Ti 2p-orbital that appears in a binding energy region of 455 eV to 462 eV;
a positive electrode; and
a nonaqueous electrolyte,
wherein the negative electrode active material particles have a layer of a lithium titanate having a rock salt structure on at least a part of the surface thereof, and
the layer of the lithium titanate having the rock salt structure has a thickness of 5 nm to 50 nm.

2. The nonaqueous electrolyte battery according to claim 1 , wherein
the layer of the lithium titanate having the rock salt structure has a thickness of 5 nm to 30 nm.

3. The nonaqueous electrolyte battery according to claim 1 , wherein the negative electrode comprises a negative electrode current collector and a negative electrode mixture layer supported on the negative electrode current collector,
the negative electrode mixture layer comprises the negative electrode active material particles, a conductive agent, and a binder,
the negative electrode mixture layer has a thickness of t A , and the negative electrode current collector has a thickness of t AC , and
the thickness t A and the thickness t AC satisfy the following relationship of 2≤t A /t AC ≤20.

4. The nonaqueous electrolyte battery according to claim 3 , wherein 7≤t A /t AC ≤20.

5. The nonaqueous electrolyte battery according to claim 1 , wherein the positive electrode comprises a positive electrode current collector and a positive electrode mixture layer supported on the positive electrode current collector,
the positive electrode mixture layer comprises a positive electrode active material, a conductive agent, and a binder,
the positive electrode mixture layer has a thickness t C , and the positive electrode current collector has a thickness t CC , and
the thickness t C and the thickness t CC satisfy the following relationship of 2≤t C /t CC ≤20.

6. The nonaqueous electrolyte battery according to claim 5 , wherein 5.5≤t C /t CC ≤20.

7. The nonaqueous electrolyte battery according to claim 1 , wherein the nonaqueous electrolyte comprises at least one lithium salt containing an anion of which has a van der Waals ionic radius within a range of 0.25 nm to 0.4 nm.

8. The nonaqueous electrolyte battery according to claim 1 , wherein the nonaqueous electrolyte comprises at least one lithium salt selected from the group consisting of a lithium hexafluorophosphate, a lithium hexafluoroarsenate, and lithium trifluoromethanesulfonate.

9. The nonaqueous electrolyte battery according to claim 8 , wherein a concentration of the at least one lithium salt in the nonaqueous electrolyte is 0.5 to 2 mol/L.

10. A battery pack comprising the nonaqueous electrolyte batteries each according to claim 1 .

Assignees

• Toshiba Kk

Inventors

• Kuriyama Hiromichi
• Saruwatari Hidesato
• Satake Hideki
• Yamamoto Dai

Classifications

• H01M4/485 Primary

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/0416

  involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence) · CPC title

• H01M4/131 Primary

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

• H01M10/0566

  Liquid materials · CPC title