Thin primary cell

• US 5,019,467 A
• Filed: 07/10/1989
• Issued: 05/28/1991
• Est. Priority Date: 11/13/1987
• Status: Expired due to Fees

• Current Assignee: Kimoto Company Limited
• Original Assignee: Kimoto Company Limited
• Inventors: Fujiwara, Yasuo
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US07/377,741
• Time in Patent Office: 687 Days
• Field of Search: 429/127, 429/162, 429/152, 429/192, 429/124, 29/623.5
• US Class Current: 429/127
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A thin primary cell formed with a combination of a positive current collection layer, a positive active layer, a solid polyelectrolyte layer and a thin metallic film layer which are successively laminated onto an insulating material. Since this thin primary cell employs a solid polyelectrolyte as an electrolyte, it is not only free from liquid leakage but also formable on a film or sheet.

Claims

1. A thin primary cell, in the form of at least one ply of a flexible film of a thickness sufficiently thin to allow the film to be cut by scissors to a length providing a selected size and capacity, said film having a thickness of not more than 0.10 mm and consisting of the following layers, in succession:

a positive current collection layer composed of a first polymer and a particulate conductive material selected from the group consisting of carbon grains, carbon fibers, graphite and metallic oxides dispersed in a matrix of said first polymer and having a thickness of 0.1-20 μ

m;

a positive active layer consisting essentially of a particulate manganese dioxide dispersed in a second polymer and having a thickness of 0.1-20 μ

m;

a solid polyelectrolyte layer composed of a matrix of a non-crystalline polymer and an alkali metal salt dispersed in said non-crystalline polymeric matrix and having a thickness of 0.1-10 μ

m; and

a thin metallic film layer having a thickness of 1-50 μ

m.

2. A thin primary cell as claimed in claim 1, wherein said positive current collection layer is composed of a metallix oxide and said first polymer.

3. A thin primary cell as claimed in claim 1, wherein said alkali metal salt is a lithium salt.

4. The thin primary cell of claim 1 wherein said non-crystalline polymer is a polymer whose glass point is less than 10°

C. and which has active molecular motion at room temperature.

5. The thin primary cell of claim 1 wherein said non-crystalline polymer is selected from the group consisting of polyethylene oxide (PEO), polymethoxy polyethylene glycol methacrylate, polyvinyl pyridine, polysiloxane, polypropylene oxide, segmented polyurethane, urea-polyurethane, polyphosphazene, cellulose, polystyrene and polypeptide.

6. The thin primary cell of claim 1 formed by the process comprising the steps of, in succession:

coating said substrate with a liquid blend of said first polymer and said particulate conductive material to form said positive current collection layer;

coating said positive current collection layer with a liquid blend of said particulate manganese dioxide and said second polymer to form said positive active layer;

coating said positive active layer with a liquid blend of said non-crystalline polymer and said alkali metal salt to form said solid polyelectrolyte layer; and

coating said solid polyelectrolyte layer with said metallic film by vacuum deposition, sputtering, ion-plating or non-electrolytic plating.