Solid state electrochemical cell having microroughened current collector

• US 5,436,091 A
• Filed: 11/22/1993
• Issued: 07/25/1995
• Est. Priority Date: 05/11/1989
• Status: Expired due to Fees

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Fauteux, Denis G., Shackle, Dale R.
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US08/155,547
• Time in Patent Office: 610 Days
• Field of Search: 429/191, 429/192, 429/198, 429/212, 429/218, 429/213, 429/217, 429/245
• US Class Current: 429/304
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 4/02 Electrodes composed of, or comprising, active material
• CPC Class Codes: H01M 4/64 Carriers or collectors

Abstract

A solid state laminar electrochemical cell comprising:

an alkali metal anode layer;

a solid ionically conductive electrolyte layer;

a cathode composition layer; and

a current collector;

wherein said electrolyte layer is interposed between said alkali metal anode layer and said cathode layer and said cathode layer is interposed between said electrolyte layer and said current collector, the surface of said current collector which contacts said electrolyte layer being microroughened to enable the cathode layer to tightly adhere to said current collector is disclosed.

Claims

1. A solid state laminar electrochemical cell comprising:

an alkali metal anode layer;

a solid ionically conductive electrolyte layer including an ionizable alkali metal salt or alkaline earth metal salt, an inert solvent for the salt, and a polymerizable material;

a cured cathode composition layer which is cured using radiation or thermal initiated polymerization wherein said cathode composition layer includes an ionically conductive electrolyte comprising an ionizable alkali metal salt or alkaline earth salt and an inert liquid solvent for said salt; and

a current collector including a metal foil substrate;

with the electrolyte layer interposed between said alkali metal anode layer and said cured cathode layer, and said cathode layer interposed between said electrolyte layer and said current collector, the surface of said current collector which contacts said cathode layer being micro-toughened for providing low impedance between the collector and the cathode layer by enabling the cathode layer to tightly adhere to said current collector, and wherein the current collector and cured Cathode composition layer forms a collector/cathode composition interface and wherein the impedance at the collector/cathode composition interface is less than 10 ohms/cm².

2. The cell according to claim 1 wherein the impedance at the collector/cathode composition interface is less than 5 ohms/cm².

3. A solid state laminar electrochemical cell comprising:

an alkali metal anode layer;

a solid ionically conductive electrolyte layer including an ionizable alkali metal salt or alkaline earth metal salt, an inert solvent for the salt, and a polymerizable material;

a cured cathode composition layer which is cured using radiation or thermal initiated polymerization wherein said cathode composition layer includes an ionically conductive electrolyte comprising an ionizable alkali metal salt or alkaline earth salt and an inert liquid solvent for said salt; and

a current collector including a metal foil substrate;

with the electrolyte layer interposed between said alkali metal anode layer and said cured cathode layer, and said cathode layer interposed between said electrolyte layer and said current collector, the surface of said current collector which contacts said cathode layer being micro-roughened for providing low impedance between-the current collector and the Cathode layer by enabling the cathode layer to tightly adhere to said current collector wherein said micro-toughened surface is produced by electrondepositing metal particles on said foil and wherein said metal foil substrate and said electrondeposited metal comprise nickel and wherein the current collector and cured cathode composition layer forms a collector/cathode composition interface and wherein the impedance at the collector/cathode composition interface is less than 10 ohms/cm².

4. The cell according to claim 3 wherein the impedance at the collector/cathode composition interface is less than 5 ohms/cm².

5. A solid state laminar electrochemical cell comprising:

an alkali metal anode layer;

a solid ionically conductive electrolyte layer including an ionizable alkali metal salt or alkaline earth metal salt, an inert solvent for the salt, and a polymerizable material;

a cured cathode composition layer which is cured using radiation or thermal initiated polymerization wherein said cathode composition layer includes an ionically conductive electrolyte comprising an ionizable alkali metal salt or alkaline earth salt and an inert liquid solvent for said salt; and

a current collector including a metal foil substrate;

with the electrolyte layer interposed between said alkali metal anode layer and said cured cathode layer, and said cathode layer interposed between said electrolyte layer and said current collector, the surface of said current collector which contacts said cathode layer being micro-toughened for providing low impedance between the current collector and the cathode layer by enabling the cathode layer to tightly adhere to said current collector, wherein said salt is a salt of a cation selected from the group consisting of Li⁺, Na⁺, K⁺, Mg²⁺, Ca²⁺ and NH₄⁺ and an anion selected from the group consisting of I^-, ClO₄^-, BF₄^-, AsF₆^-, PF₆^-, CF₃ SO₃^-, CF₃ CO₃^-, B₁₂ H₁₂^2-, B₁₀ Cl₁₀^2-, and Bφ

₄^-, where φ

is C₆ H₅, an alkyl chain or an aryl chain, wherein said salt cation and said salt anion are maintained in stoichiometric amounts, and wherein the current collector and cured cathode composition layer forms a collector/cathode composition interface and wherein the impedance at the collector/cathode composition interface is less than 10 ohms/cm².

6. The cell according to claim 5 wherein the impedance at the collector/cathode composition interface is less than 5 ohms/cm².

7. A solid state laminar electrochemical cell comprising:

an alkali metal anode layer;

a solid ionically conductive electrolyte layer including an ionizable alkali metal salt or alkaline earth metal salt, an inert solvent for the salt, and a polymerizable material;

a cured cathode composition layer which is cured using radiation or thermal initiated polymerization wherein said cathode composition layer includes an ionically conductive electrolyte comprising an ionizable alkali metal salt or alkaline earth salt and an inert liquid solvent for said salt; and

a current collector including a metal foil substrate;

with the electrolyte layer interposed between said alkali metal anode layer and said cured cathode layer and said cathode layer interposed between said electrolyte layer and said current collector, the surface of said current collector which contacts said cathode layer being micro-roughened for providing low impedance between the current collector and the cathode layer by enabling the cathode layer to tightly adhere to said current collector wherein said anode layer comprises lithium foil, a metal foil coated with a layer of lithium or a lithium alloy, wherein said cathode composition comprises an intercalation compound, an electrically conductive filler and an ionically conductive electrolyte, and wherein the current collector and cured cathode composition layer forms a collector/cathode composition interface and wherein the impedance at the collector/cathode composition interface is less than 10 ohms/cm².

8. The cell according to claim 7 wherein the impedance at the collector/cathode composition interface is less than 5 ohms/cm².