Energy storage device and method for manufacturing the same

• US 10,283,765 B2
• Filed: 08/17/2015
• Issued: 05/07/2019
• Est. Priority Date: 06/30/2010
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Haske, Wojciech
• Application Number:
  US14/827,444
• Publication Number:
  US 20150357640A1
• Time in Patent Office: 1,359 Days
• Field of Search: None
• CPC Class Codes: H01G 11/06 with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/50 specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
• CPC Class Codes: H01G 11/66 Current collectors
• CPC Class Codes: H01G 11/76 specially adapted for integration in multiple or stacked hybrid or EDL capacitors
• 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 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0419 involving spraying
• CPC Class Codes: H01M 4/0426 Sputtering
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• 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: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10T 29/49108 : Electric battery cell making
• CPC Class Codes: Y10T 29/49115 : including coating or impregnating

Abstract

Provided are an energy storage device including an electrode in which lithium is introduced into a silicon layer and a method for manufacturing the energy storage device. A silicon layer is formed over a current collector, a solution including lithium is applied on the silicon layer, and heat treatment is performed thereon; thus, at least lithium can be introduced into the silicon layer. By using the solution including lithium, even when the silicon layer includes a plurality of silicon microparticles, the solution including lithium can enter a space between the microparticles and lithium can be introduced into the silicon microparticles which are in contact with the solution including lithium. Moreover, even when the silicon layer is a thin silicon film or includes a plurality of whiskers or whisker groups, the solution can be uniformly applied; accordingly, lithium can be included in silicon easily.

Claims

1. An energy storage device comprising:

a negative electrode comprising;

a negative electrode current collector;

a negative electrode active material layer comprising silicon and lithium over the negative electrode current collector; and

a conductive layer comprising titanium over the negative electrode active material layer; and

a positive electrode comprising a positive electrode active material layer,

wherein the positive electrode comprises a material capable of reversibly electrosorbing lithium ions,

wherein the material capable of reversibly electrosorbing lithium ions is any one of active carbon, a conductive polymer, and a polyacene organic semiconductor, and

wherein a lithium concentration in a superficial portion of the negative electrode active material layer is higher than a lithium concentration in a portion of the negative electrode active material layer which is close to the negative electrode current collector before an initial charging or discharging of the energy storage device.

2. The energy storage device according to claim 1, wherein the conductive layer is in contact with the negative electrode active material layer.

3. The energy storage device according to claim 1, wherein the negative electrode current collector comprises titanium.

4. The energy storage device according to claim 1, wherein a thickness of the conductive layer is greater than or equal to 0.1 nm and less than or equal to 10 nm.

5. The energy storage device according to claim 1, wherein silicide is formed between the negative electrode active material layer and the conductive layer.

6. The energy storage device according to claim 1, wherein a carbon layer is attached to the superficial portion of the negative electrode active material layer.

7. The energy storage device according to claim 1, wherein the material capable of reversibly electrosorbing lithium ions does not comprise lithium.

8. An energy storage device comprising:

a negative electrode comprising;

a negative electrode current collector;

a negative electrode active material layer comprising silicon and lithium over the negative electrode current collector; and

a conductive layer comprising titanium over the negative electrode active material layer; and

a positive electrode comprising a positive electrode active material layer,

wherein the positive electrode comprises a material capable of reversibly electrosorbing lithium ions,

wherein the material capable of reversibly electrosorbing lithium ions is any one of active carbon, a conductive polymer, and a polyacene organic semiconductor,

wherein the negative electrode active material layer comprises a plurality of whiskers of crystalline silicon, and

wherein a lithium concentration in a superficial portion of the negative electrode active material layer is higher than a lithium concentration in a portion of the negative electrode active material layer which is close to the negative electrode current collector before an initial charging or discharging of the energy storage device.

9. The energy storage device according to claim 8, wherein the conductive layer is in contact with the negative electrode active material layer.

10. The energy storage device according to claim 8, wherein the negative electrode current collector comprises titanium.

11. The energy storage device according to claim 8, wherein a thickness of the conductive layer is greater than or equal to 0.1 nm and less than or equal to 10 nm.

12. The energy storage device according to claim 8, wherein silicide is formed between the negative electrode active material layer and the conductive layer.

13. The energy storage device according to claim 8, wherein a carbon layer is attached to the superficial portion of the negative electrode active material layer.

14. The energy storage device according to claim 8, wherein the material capable of reversibly electrosorbing lithium ions does not comprise lithium.