Electrode, secondary battery, battery pack, and vehicle

Patent metadata

Field	Value
Publication number	US-11217793-B2
Application number	US-202016804546-A
Country	US
Kind code	B2
Filing date	Feb 28, 2020
Priority date	Sep 17, 2019
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

According to one embodiment, an electrode is provided. The electrode includes the active material-containing layer formed on the current collector and including active material particles. The particle size distribution chart obtained by the laser diffraction scattering method for the active material particles includes the first region and the second region. The first particle group included in the first region includes the first active material particles, and the second particle group included in the second region includes second active material particles. The carbon coverage of the first particle group is higher than the carbon coverage of the second particle group.

First claim

What is claimed is:

1. An electrode comprising:
a current collector; and
an active material-containing layer formed on the current collector and comprising active material particles, wherein
the active material particles comprise first active material particles and second active material particles,
the first active material particles comprise core particles containing monoclinic niobium-titanium composite oxide, and a carbon material layer with which at least a part of surfaces of the core particles is coated,
the second active material particles comprise monoclinic niobium-titanium composite oxide,
a particle size distribution chart obtained by a laser diffraction scattering method for the active material particles comprises a first region corresponding to a particle size of smaller than a median diameter d50 and a second region corresponding to a particle size of the median diameter d50 or larger,
a first particle group comprised in the first region comprises the first active material particles, and a second particle group comprised in the second region comprises the second active material particles, and
a carbon coverage of the first particle group is higher than a carbon coverage of the second particle group.

2. The electrode according to claim 1 , wherein the carbon coverage of the first particle group is in a range from 30% to 100%.

3. The electrode according to claim 1 , wherein the carbon coverage of the second particle group is in a range from 0% to 20%.

4. The electrode according to claim 1 , wherein the carbon coverage of the first particle group is in a range from 60% to 100%.

5. The electrode according to claim 1 , wherein the median diameter d50 is in a range from 1.0 μm to 2.0 μm.

6. The electrode according to claim 1 , wherein in the particle size distribution chart, the first region has a mode diameter in a range from 0.15 μm to 2.0 μm.

7. The electrode according to claim 1 , wherein in the particle size distribution chart, the second region has a mode diameter in a range from 2.5 μm to 10 μm.

8. The electrode according to claim 1 , wherein an electrode density is in a range from 2.5 g/cm 3 to 2.9 g/cm 3 .

9. The electrode according to claim 1 , wherein the monoclinic niobium-titanium composite oxide comprised in the first active material particles and the monoclinic niobium-titanium composite oxide comprised in the second active material particles are, each independently, at least one selected from the group consisting of a composite oxide represented by General Formula Li x Ti 1−y M1 y Nb 2−z M2 z O 7+δ , and a composite oxide represented by General Formula Li x Ti 1−y M3 y+z Nb 2−z O 7−δ ,
M1 is at least one selected from the group consisting of Zr, Si, and Sn, M2 is at least one selected from the group consisting of V, Ta, and Bi, and M3 is at least one selected from the group consisting of Mg, Fe, Ni, Co, W, Ta, and Mo, and
x satisfies 0≤x≤5, y satisfies 0≤y<1, z satisfies 0≤z<2, and δ satisfies −0.3≤δ≤0.3.

10. A secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte, wherein
the negative electrode is the electrode according to claim 1 .

11. A battery pack comprising the secondary battery according to claim 10 .

12. The battery pack according to claim 11 , further comprising:
an external power distribution terminal; and
a protective circuit.

13. The battery pack according to claim 11 , further comprising:
a plurality of the secondary battery, wherein
the secondary batteries are electrically connected in series, in parallel, or in a combination of series connection and parallel connection.

14. A vehicle comprises the battery pack according to claim 11 .

15. The vehicle according to claim 14 , further comprising a mechanism configured to convert kinetic energy of the vehicle into regenerative energy.

Assignees

• Toshiba Kk

Inventors

• Kanai Yuta
• Sasakawa Tetsuya
• Hoshina Keigo
• Harada Yasuhiro
• Takami Norio

Classifications

• H01M50/20

  Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders (structural combination of accumulators with charging apparatus H01M10/46) · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M10/425 Primary

  Structural combination with electronic components, e.g. electronic circuits integrated to the outside of the casing (printed circuits H05K1/00) · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title