Low resistance rechargeable lithium-ion battery

• US 5,587,253 A
• Filed: 08/03/1995
• Issued: 12/24/1996
• Est. Priority Date: 03/05/1993
• Status: Expired due to Term

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Bell Communications Research, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Gozdz, Antoni S., Warren, Paul C., Schmutz, Caroline N.
• Primary Examiner(s): Maples, John S.
• Application Number:
  US08/510,835
• Time in Patent Office: 509 Days
• Field of Search: 429/245, 429/217, 429/192
• US Class Current: 429/316
• CPC Class Codes: C08J 2327/16 Homopolymers or copolymers of vinylidene fluoride
• CPC Class Codes: C08J 9/28 by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• 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 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 2300/0025 Organic electrolyte
• CPC Class Codes: H01M 2300/0085 Immobilising or gelification of electrolyte
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/72 Grids
• CPC Class Codes: H01M 4/74 Meshes or woven material; Expanded metal
• CPC Class Codes: H01M 50/426 Fluorocarbon polymers
• CPC Class Codes: H01M 50/489 Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
• CPC Class Codes: H01M 50/497 Ionic conductivity
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• CPC Class Codes: H01M 6/32 activated through external addition of electrolyte or of electrolyte components
• 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 perforate current collector element (21) embedded within at least one of its polymeric intercalation electrodes (23) reduces the internal resistance of a flexible rechargeable lithium-ion battery (20).

Claims

1. A rechargeable lithium-ion battery structure comprising positive and negative electrode layer elements having a separator element disposed therebetween and current collectors associated therewith, each of said elements comprising a flexible, polymeric matrix film composition and being bonded to contiguous elements at its respective interfaces to form a unitary flexible structure characterized in that

a) said positive electrode layer element comprises a composition of a lithium ion intercalating compound selected from the group consisting of Li_x Mn₂ O₄, Li_x CoO₂, and Li_x NiO₂ ;

and

b) at least one of said current collectors is embedded within its associated electrode layer.

2. A battery structure according to claim 1 wherein said embedded collector is substantially coextensive with its associated electrode and is perforate, whereby the composition of said electrode penetrates said collector to maintain ionic conductivity through said electrode layer.

3. A battery structure according to claim 2 wherein said embedded collector is disposed substantially equidistant from the surfaces of said electrode layer, thereby minimizing the internal resistance of said structure.

4. A battery structure according to claim 1 wherein at least one of said current collectors is embedded within said electrode layer at a location contiguous to an electrode/separator interface.

5. A battery structure according to claim 4 wherein said electrode layer comprises a composition of a lithium intercalating material consisting essentially of carbon.

6. A battery structure according to claim 2 wherein each of a plurality of said collectors is embedded within its respective associated electrode.

7. A battery structure according to claim 6 wherein the plurality of electrodes comprises a like polarity pair disposed symmetrically about an electrode of opposite polarity.

8. A rechargeable lithium-ion battery structure comprising:

a) a plurality of positive electrode elements made of a flexible polymer composition containing a lithiated intercalation compound;

b) a negative electrode element made of a flexible polymeric matrix composition containing carbon as a material capable of lithium intercalation, wherein said negative electrode element is positioned between each of said positive electrodes;

c) a plurality of separator elements composed of a flexible polymeric film composition capable of being made ionically conductive by incorporation of an organic solution of a dissociable lithium salt which can provide ionic mobility, at least one of said separator elements being disposed on either side of said negative electrode, thereby separating the negative electrode from the positive electrodes;

d) a plurality of current collectors, wherein a current collector is embedded within each of said positive electrodes and said negative electrode; and

e) wherein each of said elements is bonded to contiguous elements to form a unitary flexible structure.

9. A battery structure according to claim 8 wherein said current collectors are made of aluminum or copper.

10. A battery structure according to claim 9 wherein said current collectors are perforate.

11. A battery structure according to claim 10 wherein said current collectors are made of a metal foil grid.

12. A battery structure according to claim 8 wherein the flexible polymeric matrix film composition is a plasticized polyvinylidene fluoride copolymer.