Energy storage device and method for manufacturing the same

• US 9,112,224 B2
• Filed: 06/20/2011
• Issued: 08/18/2015
• 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): Barcena, Carlos
• Assistant Examiner(s): Haske, Wojciech
• Application Number:
  US13/163,879
• Publication Number:
  US 20120003535A1
• Time in Patent Office: 1,520 Days
• Field of Search: None
• US Class Current: 1/1
• 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. A method for manufacturing an energy storage device, comprising the steps of:

forming a silicon layer over a current collector;

applying a solution comprising lithium and glucose on the silicon layer; and

performing heat treatment so that the lithium is introduced from the solution into the silicon layer,

wherein a lithium concentration in a superficial portion of the silicon layer becomes higher than a lithium concentration in a portion of the silicon layer which is close to the current collector by the heat treatment, and

wherein the heat treatment is performed at a temperature higher than or equal to 500°

C. and lower than or equal to 700°

C.

3. The method for manufacturing an energy storage device, according to claim 1,

further comprising the step of forming a mixed layer between the current collector and the silicon layer,

wherein the mixed layer is formed using silicon and a metal element included in the current collector.

4. The method for manufacturing an energy storage device, according to claim 1,

wherein the silicon layer is a negative electrode active material layer.

7. The method for manufacturing an energy storage device, according to claim 1, wherein the solution contains one material selected from lithium hydroxide, lithium oxide, lithium carbonate, lithium chloride, lithium metasilicate, lithium orthosilicate, lithium iodide, lithium acetate, lithium phosphate, and lithium nitrate.

2. A method for manufacturing an energy storage device, comprising the steps of:

forming a silicon layer over a current collector;

applying a liquid in which glucose is contained and in which a particle comprising lithium is dispersed on the silicon layer; and

performing heat treatment so that the lithium is introduced from the liquid into the silicon layer,

wherein a lithium concentration in a superficial portion of the silicon layer becomes higher than a lithium concentration in a portion of the silicon layer which is close to the current collector by the heat treatment, and

wherein the heat treatment is performed at a temperature higher than or equal to 500°

C. and lower than or equal to 700°

C.

5. The method for manufacturing an energy storage device, according to claim 2,

further comprising the step of forming a mixed layer between the current collector and the silicon layer,

wherein the mixed layer is formed using silicon and a metal element included in the current collector.

6. The method for manufacturing an energy storage device, according to claim 2,

wherein the silicon layer is a negative electrode active material layer.

8. The method for manufacturing an energy storage device, according to claim 2, wherein the liquid contains one material selected from lithium hydroxide, lithium oxide, lithium carbonate, lithium chloride, lithium metasilicate, lithium orthosilicate, lithium iodide, lithium acetate, lithium phosphate, and lithium nitrate.

9. A method for manufacturing an energy storage device, comprising the steps of:

forming a silicon layer over a current collector;

applying a solution comprising lithium and an organic substance on the silicon layer; and

performing heat treatment so that the lithium is introduced from the solution into the silicon layer and the organic substance forms a carbon layer on the silicon layer,

wherein a lithium concentration in a superficial portion of the silicon layer becomes higher than a lithium concentration in a portion of the silicon layer which is close to the current collector by the heat treatment, and

wherein the heat treatment is performed at a temperature higher than or equal to 500°

C. and lower than or equal to 700°

C.

10. A method for manufacturing an energy storage device, comprising the steps of:

forming a silicon layer over a current collector;

applying a liquid in which an organic substance is contained and in which a particle comprising lithium is dispersed on the silicon layer; and

performing heat treatment so that the lithium is introduced from the liquid into the silicon layer and the organic substance forms a carbon layer on the silicon layer,

wherein a lithium concentration in a superficial portion of the silicon layer becomes higher than a lithium concentration in a portion of the silicon layer which is close to the current collector by the heat treatment, and

wherein the heat treatment is performed at a temperature higher than or equal to 500°

C. and lower than or equal to 700°

C.