Current collector for lithium ion battery

• US 5,547,782 A
• Filed: 03/13/1995
• Issued: 08/20/1996
• Est. Priority Date: 03/02/1994
• Status: Expired due to Term

• Current Assignee: Electrovaya Incorporated
• Original Assignee: Electrofuel, Inc.
• Inventors: Dasgupta, Sankar, Jacobs, James K.
• Primary Examiner(s): Maples, John S.
• Application Number:
  US08/402,359
• Time in Patent Office: 526 Days
• Field of Search: 429/245, 429/235, 429/237, 429/233, 429/194, 429/209
• US Class Current: 429/322
• 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 4/663 containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 4/664 Ceramic materials
• CPC Class Codes: H01M 4/668 Composites of electroconductive material and synthetic resins
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

An improved lithium ion battery is described wherein corrosion of the current collector in contact with the electrode face is greatly reduced. In one embodiment an electrically conductive, ceramic layer is inserted between the current collector and the corresponding major face of the lithium ion battery. In another embodiment the metallic current collector plate is replaced by an electrically conductive laminated organic polymer having electrically conductive particles dispersed therein.

Claims

1. In a lithium ion battery, having a positive electrode comprising a positive active material capable of reacting with lithium ions in discharging said battery and releasing lithium ions in charging said battery, said positive electrode having two opposing major faces, a negative electrode comprising a negative active material capable of releasing lithium ions in discharging said battery and intercalating lithium ions in charging said battery, said negative electrode having two opposing major faces, a non-aqueous electrolyte containing a lithium salt capable of ionic dissociation, a first current collector in contact with a distal major face of said positive electrode, a second current collector in contact with a distal major face of said negative electrode, and metallic electrical lead means in juxtaposed contact position with the external face of each of said current collectors, the improvement comprising that said first current collector in contact with said distal major face of said positive electrode is an electrically conductive, continuous and coherent polymer layer, said polymer layer consisting essentially of an electrically non-conductive, continuous and coherent polymer laminate having a thickness, and said continuous and coherent polymer laminate is having dispersed therein more than 35 vol. % electrically conductive particles selected from the group consisting of titanium nitride, zirconium nitride, fine carbon, carbon black and carbon fibres, said conductive particles having major and minor dimensions.

2. An improved lithium ion battery as claimed in claim 1, wherein the average minor dimension of said electrically conductive particles dispersed in said electrically non-conductive continuous and coherent polymer laminate is less than the thickness of said continuous and coherent polymer laminate.

3. An improved lithium ion battery as claimed in claim 1, wherein said thickness of said electrically non-conductive, continuous and coherent polymer laminate is less than 300 μ

m.

4. An improved lithium ion battery as claimed in claim l, further comprising that said second current collector in contact with said distal major face of said negative electrode is a second electrically conductive, continuous and coherent polymer layer, said second electrically conductive, continuous and coherent polymer layer consisting essentially of an electrically non-conductive, continuous and coherent polymer laminate having a thickness, and said second continuous and coherent polymer laminate is having dispersed therein more than 35 vol. % electrically conductive particles selected from the group consisting of titanium nitride, zirconium nitride, fine carbon, carbon black and carbon fibres, said conductive particles having major and minor dimensions.

5. An improved lithium ion battery as claimed in claim 4, wherein said thickness of said second electrically non-conductive, continuous and coherent polymer laminate is less than 300 μ

m.