Battery and non-aqueous electrolyte secondary battery using the same

• US 20050064291A1
• Filed: 09/02/2004
• Published: 03/24/2005
• Est. Priority Date: 09/18/2003
• Status: Abandoned Application

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Sato, Toshitada, Bito, Yasuhiko, Nakai, Miyuki, Igaki, Emiko
• Application Number:
  US10/933,147
• Publication Number:
  US 20050064291A1
• Time in Patent Office: Days
• US Class Current: 429/233
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• CPC Class Codes: H01M 4/40 Alloys based on alkali metals
• CPC Class Codes: H01M 4/405 Alloys based on lithium
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A negative electrode for a non-aqueous electrolyte secondary battery including a current collector, and an electrode material layer including an electrode material capable of reversibly absorbing and desorbing Li ions is provided. The electrode material includes at least one element selected from the group consisting of Si, Sn and Al; the surface of the current collector is provided with protrusions; the electrode material layer is disposed on the surfaces of the current collector and the protrusions; and the protrusion has a portion facing the surface of the current collector other than a portion that is brought into contact with the current collector. Thus, a negative electrode for a non-aqueous electrolyte battery having high properties such as an energy density, charging/discharging cycle property, and the like, and a non-aqueous electrolyte secondary battery can be provided.

Claims

1. A negative electrode for a non-aqueous electrolyte secondary battery capable of reversibly absorbing and desorbing Li ions, the negative electrode comprising:

a current collector; and

an electrode material layer comprising an electrode material capable of reversibly absorbing and desorbing Li ions;

wherein the electrode material comprises at least one element selected from the group consisting of Si, Sn and Al;

the surface of the current collector is provided with protrusions;

the electrode material layer is disposed on the surfaces of the current collector and the protrusions; and

the protrusion has a portion facing the surface of the current collector other than a portion that is brought into contact with the current collector.

2. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion has a portion whose cross-sectional area cut in the direction parallel to the surface of the current collector exceeds an area of a portion that is brought into contact with the current collector.

3. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion has at least one shape selected from the group consisting of a zigzag shape and an undulated shape.

4. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the average height of the protrusion from the surface of the current collector is 15% or more and 75% or less with respect to the thickness of the electrode material layer.

5. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the maximum height of the protrusion from the surface of the current collector is 95% or less with respect to the thickness of the electrode material layer.

6. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1,

wherein the protrusion comprises a column portion linked to the surface of the current collector;

and a covering portion linked to the end of the column portion opposite side to the current collector; and

wherein the covering portion has a portion whose cross-sectional area cut in the direction parallel to the surface of the current collector exceeds the cross-sectional area of the column portion cut in the direction parallel to the surface of the current collector.

7. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 6, wherein the protrusion has a plurality of the covering portions.

8. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion, when cut in the direction perpendicular to the surface of the current collector, has at least one shape selected from the group consisting of a mushroom shape, an umbrella shape, a nail head shape, a laterally-facing L-shape, a reverse J-shape, a hook shape, a T-shape, a Y-shape, a screw shape, a cauliflower shape and a pile shape.

9. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion comprises a conductive material.

10. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion comprises a metallic particle.

11. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 10, wherein the metallic particle comprises at least one element selected from the group consisting of Cu, Ni and Ti.

12. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the protrusion comprises a metallic fiber.

13. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the current collector comprises a metallic fiber, and the protrusion has a pile shape formed by raising the metallic fiber.

14. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 13, wherein the metallic fiber comprises at least one selected from the group consisting of Cu, Ni, and stainless steel.

15. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the electrode material is a powder form having a maximum particle size of 0.01 μ

m or more and 45 μ

m or less.

16. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1, wherein the electrode material has a form of a thin film.

17. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 1,

wherein the current collector comprises a macromolecular film and a conductor layer;

the surface of the macromolecular film is provided with the protrusions; and

the conductor layer is formed along the surface shape of the macromolecular film.

18. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 17, wherein the macromolecular film is a polyolefin film.

19. The negative electrode for a non-aqueous electrolyte secondary battery according to claim 17, wherein the conductor layer comprises at least one element selected from the group consisting of Cu, Ni and Ti.

20. A non-aqueous electrolyte secondary battery, comprising:

a negative electrode for a non-aqueous electrolyte secondary battery, which is capable of reversibly absorbing and desorbing Li ions;

a positive electrode capable of reversibly absorbing and desorbing Li ions; and

an electrolyte having a Li ion conductivity;

wherein the negative electrode comprises a current collector, and an electrode material layer comprising an electrode material capable of reversibly absorbing and desorbing Li ions;

the electrode material comprises at least one element selected from the group consisting of Si, Sn and Al;

the surface of the current collector is provided with protrusions;

the electrode material layer is disposed on the surfaces of the current collector and the protrusions; and

the protrusion has a portion facing the surface of the current collector other than a portion that is brought into contact with the current collector.