Method for manufacturing a multi-layered thin film for use as an anode in a lithium secondary battery

• US 7,316,867 B2
• Filed: 11/29/2004
• Issued: 01/08/2008
• Est. Priority Date: 08/25/2001
• Status: Expired due to Term

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Park, Young-sin, Lee, Sung-man, Oh, Joo-yeal, Baik, Hong-koo
• Primary Examiner(s): Cantelmo; Gregg
• Assistant Examiner(s): Wang; Eugenia
• Application Number:
  US10/997,882
• Publication Number:
  US 20050074673A1
• Time in Patent Office: 1,135 Days
• Field of Search: 429/231.95, 429/219, 204/192.12, 204/192.15, 204/192.17, 204/192.23
• US Class Current: 429/231.95
• CPC Class Codes: H01M 10/0436 Small-sized flat cells or batteries for portable equipment
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• 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 4/1391 of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/1397 of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/366 as layered products
• 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 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/54 of silver
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A thin film for an anode of a lithium secondary battery having a current collector and an anode active material layer formed thereon is provided. The anode active material layer is a multi-layered thin film formed by stacking a silver (Ag) layer and a silicon-metal (Si-M) layer having silicon dispersed in a base made from metal reacting with silicon while not reacting with lithium. The cycle characteristic of the thin film for an anode can be improved by suppressing the volumetric expansion and shrinkage of Si occurring during charging/discharging cycles. Thus, a lithium secondary battery with improved life characteristics by employing the thin film for an anode, which greatly improves the chemical, mechanical stability of the interface between an electrode and an electrolyte.

Claims

1. A method for manufacturing a multi-layered thin film structure for use as an anode of a lithium secondary battery comprising:

(a) forming a thin film of silicon-metal (Si-M) by depositing a metal reacting with silicon and silicon on a current collector to form a thin film having a layer thickness of 50 to 450 Å

while not reacting with lithium;

(b) forming a thin film of silver (Ag) by depositing Ag on the Si-M layer in form of a thin film silver layer having a thickness of 10 to 70 Å

; and

(c) forming a multi-layered stacked thin film structure on the current collector by repeating the steps (a) and (b) more than one time.

2. The method according to claim 1, wherein the metal (M) is at least one selected from the group consisting of vanadium (V), manganese (Mn), titanium (Ti), nickel (Ni), platinum (Pt), zirconium (Zr);

chromium (Cr), iron (Fe);

hafnium (Hf);

molybdenum (Mo), Niobium (Nb);

ruthenium (Ru) and tantalum (Ta).

3. The method according to claim 1, wherein the metal (M) content in the Si-M layer as an anode active material layer is in the range of 5 to 50 mol %.

4. The method according to claim 1, wherein the deposition in steps (a) and (b) to form thin film layers are each performed by a method selected from co-sputtering, e-beam evaporation and ion-beam assisted deposition.

5. The method according to claim 1, wherein the metal (M) content in the Si-M layer as an anode active material layer is in the range of 20 to 30 mol %.

6. The method according to claim 1, wherein the current collector is a copper layer.

7. The method according to claim 6, wherein said copper layer has a thickness in the range 100 to 300 nm.