Lithium secondary battery

• US 5,437,942 A
• Filed: 04/20/1993
• Issued: 08/01/1995
• Est. Priority Date: 08/21/1991
• Status: Expired due to Fees

• Current Assignee: GS Yuasa Corporation
• Original Assignee: GS Yuasa Corporation
• Inventors: Murata, Kazuo, Takeda, Kazunari, Izuchi, Syuichi, Yoshihisa, Youetsu
• Primary Examiner(s): Maples, John S.
• Application Number:
  US08/039,431
• Time in Patent Office: 833 Days
• Field of Search: 429/191, 429/192, 429/193
• US Class Current: 429/312
• 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: Y02E 60/10 Energy storage using batteries

Abstract

A lithium secondary battery includes a positive electrode, an electrolyte layer having a solid polymer electrolyte, and a negative electrode using metallic lithium or lithium alloy as an active material. The electrolyte layer includes a first layer and a second layer, and an electrolyte of the first layer in contact with the negative electrode is less reactive with a negative active material than to an electrolyte of the second layer.

Claims

1. A lithium secondary battery comprising:

a positive electrode,

an electrolyte layer having a solid polymer electrolyte, and

a negative electrode using metallic lithium alloy as an active material,

wherein the electrolyte layer comprises a first layer and a second layer, said first layer having a first electrolyte in contact with the negative electrode, said second layer having a second electrolyte, said first electrolyte being less reactive with a negative active material than said second electrolyte,

wherein the second layer includes a solvent, and the first layer includes a small amount of solvent as compared to the second layer.

2. A lithium secondary battery comprising:

a positive electrode,

an electrolyte layer having a solid polymer electrolyte, and

a negative electrode using metallic lithium alloy as an active material,

wherein the electrolyte layer comprises a first layer and a second layer, said first layer having a first electrolyte in contact with the negative electrode, said second layer having a second electrolyte, said first electrolyte being less reactive with a negative active material than said second electrolyte,

wherein the electrolyte of the first layer is a high-molecular weight compound which has a polyether structure and does not have a functional group at the end of a principal chain but includes an ionic salt, and the electrolyte of the second layer is a high-molecular weight compound which has a polyether structure, has a functional group at the end of a principal chain and includes an ionic salt.

3. A lithium secondary battery comprising:

a positive electrode,

an electrolyte layer having a solid polymer electrolyte, and

a negative electrode using metallic lithium alloy as an active material,

wherein the electrolyte layer comprises a first layer and a second layer, said first layer having a first electrolyte in contact with the negative electrode, said second layer having a second electrolyte, said first electrolyte being less reactive with a negative active material than said second electrolyte,

wherein the electrolyte of the first layer is a high-molecular weight compound which has a polyether structure and does not have a functional group at the end of a principal chain but includes an ionic salt, and the electrolyte of the second layer is a high-molecular weight compound which is formed by adding to the high-molecular weight compound of the electrolyte of the first layer a material reactive with the negative active material comprising at least one substance selected from the group consisting of beta-alumina, inorganics containing a hydroxyl group, inorganics containing a phosphoric group and inorganics containing an active hydrogen group.