Lithium polymer battery

• US 6,451,481 B1
• Filed: 03/06/2000
• Issued: 09/17/2002
• Est. Priority Date: 04/21/1999
• Status: Expired due to Term

• Current Assignee: Samsung SDI Company Limited
• Original Assignee: Samsung SDI Company Limited
• Inventors: Lee, Sung-won, Lee, Jong-min
• Primary Examiner(s): Elve, M. Alexandra
• Assistant Examiner(s): EDMONDSON, LYNNE RENEE
• Application Number:
  US09/519,849
• Time in Patent Office: 925 Days
• Field of Search: 429/218.1, 429/231.1, 429/231.8, 296/231-623
• US Class Current: 429/218.1
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0585 of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/028 Positive electrodes
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/742 perforated material
• CPC Class Codes: H01M 50/105 Pouches or flexible bags
• CPC Class Codes: H01M 6/12 with flat electrodes
• 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
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/49112 including laminating of indefinite length material
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A lithium secondary battery having a bi-cell type battery cell consisting of an anode plate, a separator fixed to both surfaces of the anode plate and a cathode plate fixed to either outer surface of the separator, wherein the cathode plate includes a cathode current collector, a front cathode sheet fixed to one surface of the cathode current collector, which is adjacent to the anode plate, and a rear cathode sheet fixed to the other surface of the cathode current collector and having a thickness different from that of the front cathode sheet.

Claims

1. A lithium secondary battery having a bi-cell battery cell including:

an anode plate,

first and second separators fixed to respective opposite surfaces of and sandwiching the anode plate, and

first and second cathode plates fixed to outer surfacer of the first and second separators, respectively, wherein each of the first and second cathode plates includes a cathode current collector, a front cathode sheet fixed to a front surface of the cathode current collector, adjacent to a respective one of the first and second separators, and a rear cathode sheet fixed to a rear surface of the cathode current collector, remote from the respective one of the first and second separators, and having a smaller thickness than the front cathode sheet, wherein the front cathode sheet is no thicker than five times the thickness of the rear cathode sheet.

2. The lithium secondary battery according to claim 1, wherein the front and rear cathode sheets include a main component selected from the group consisting of lithium-based oxide, nickel-based oxide, and manganese-based oxide.

3. A lithium secondary battery comprising:

a generally planar anode plate having an anode current collector and an anode sheet fixed to at least one surface of the anode current collector;

a generally planar cathode plate having a cathode current collector, a front cathode sheet fixed to a front surface of the cathode current collector and proximate the anode plate, and a rear cathode sheet fixed to a rear surface of the cathode current collector, remote from the anode plate, the rear cathode sheet having a thickness smaller than the front cathode sheet; and

a separator interposed between the anode plate and the cathode plate, wherein the front cathode sheet is no thicker than five times the thickness of the rear cathode sheet.