Electrode, secondary battery, battery pack, and vehicle

Patent metadata

Field	Value
Publication number	US-10741830-B2
Application number	US-201715697958-A
Country	US
Kind code	B2
Filing date	Sep 7, 2017
Priority date	Mar 24, 2017
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

According to one embodiment, an electrode including active material particles is provided. The active material particles contain monoclinic niobium-titanium composite oxide particles and an amorphous carbon body. The amorphous carbon body covers at least a part of surfaces of the monoclinic niobium-titanium composite oxide particles. A ratio S2/S1 of a carbon atom concentration S2 to a niobium atom concentration S1 at a surface of the electrode, according to X-ray photoelectron spectroscopy, is from 5 to 100.

First claim

What is claimed is:

1. A secondary battery comprising an electrode comprising active material particles and an electrolyte,
wherein:
the active material particles contain monoclinic niobium-titanium composite oxide particles and an amorphous carbon body covering at least a part of surfaces of the monoclinic niobium-titanium composite oxide particles;
at least a part of a surface of the amorphous carbon body is covered with a coating film containing carbon;
the coating film has a thickness of 10 nm to 150 nm;
a ratio S2/S1 of a carbon atom concentration S2 to a niobium atom concentration S1 at a surface of the electrode, according to X-ray photoelectron spectroscopy, is from 5 to 100;
the niobium atom concentration S1 is an intensity of an area for a peak related to Nb3d; and
the carbon atom concentration S2 is a total of intensities of areas for peaks related to C1s within a range of 286 eV to 294 eV and the peaks comprising a peak assigned to a C—O bond, a peak assigned to a C═O bond, a peak assigned to a C(═O)—O bond, and a peak assigned to a CO 3 2− bond.

2. The secondary battery according to claim 1 ,
wherein:
the surface of the electrode further comprises a phosphorus atom, and
a ratio S3/S1 of a concentration S3 of the phosphorus atom to the niobium atom concentration S1 at the surface of the electrode, according to X-ray photoelectron spectroscopy, is from 0.3 to 20;
the concentration S3 of the phosphorus atom is an intensity of an area for a peak related to P2p within a range of 133 eV to 137 eV and assigned to a PF x O y bond;
x is from 0 to 1; and
y is more than 0 and 1 or less.

3. The secondary battery according to claim 1 , wherein a thickness of the amorphous carbon body is from 1 nm to 10 nm.

4. The secondary battery according to claim 1 ,
wherein:
a Raman spectrum of the active material particles according to Raman spectroscopy has a G band within a range of 1530 cm −1 to 1630 cm −1 and a D band within a range of 1280 cm −1 to 1380 cm −1 ; and
a ratio I G /I D of peak intensity I G of the G band to peak intensity I D of the D band is 1.2 or less.

5. The secondary battery according to claim 1 , comprising:
the electrode as a negative electrode; and
a positive electrode.

6. The secondary battery according to claim 1 , wherein the electrolyte contains at least one compound selected from the group consisting of vinylene carbonate (VC), fluoroethylene carbonate (FEC), and ethylene sulfite (ES).

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

8. The battery pack according to claim 7 , further comprising:
an external power distribution terminal; and
a protective circuit.

9. The battery pack according to claim 7 ,
wherein:
the battery pack includes a plural secondary batteries; and
the plural secondary batteries are electrically connected in series, in parallel, or in combination of series and parallel.

10. A vehicle comprising the battery pack according to claim 7 .

11. The vehicle according to claim 10 , which comprises a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.

12. The secondary battery according to claim 1 , wherein the thickness of the coating film is 15 nm to 150 nm.

Assignees

• Toshiba Kk

Inventors

• Ise Kazuki
• Harada Yasuhiro
• Takami Norio

Classifications

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M2220/20

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

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M50/543

  Terminals · CPC title