Composite solid electrolytes and electrochemical devices employing the same

• US 4,990,413 A
• Filed: 01/18/1989
• Issued: 02/05/1991
• Est. Priority Date: 01/18/1989
• Status: Expired due to Fees

• Current Assignee: Devres MS Company, Hope & Lundsgaard Engineering Incorporated, MHB Joint Venture A General Partnership of Oh
• Original Assignee: MHB Joint Venture
• Inventors: Lee, Mei-Tsu, Fauteux, Denis
• Primary Examiner(s): Kalafut, Stephen J.
• Application Number:
  US07/298,169
• Time in Patent Office: 748 Days
• Field of Search: 429/191-193, 252/62.2
• US Class Current: 429/314
• CPC Class Codes: H01G 9/025 Solid electrolytes H01G11/54 takes precedence
• 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 6/18 with solid electrolyte
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A composite solid electrolyte comprising a mixture of a solid ionically conductive powder and an ionically conductive polymeric material wherein said polymeric material provides a network for containing said solid ionically conductive powder, and a method for producing the electrolyte is disclosed.

Claims

1. A composite solid electrolyte comprising a mixture of a solid ionically conductive powder and an ionically conductive polymeric material wherein said polymeric material provides a matrix for containing said solid ionically conductive powder.

2. The electrolyte of claim 1 wherein said polymeric material contains a repeating unit selected from the group consisting of:

##STR5## wherein R is hydrogen or a group Ra, -CH₂ ORa, -CH₂ OReRa, -CH₂ N(CH₃)₂, in which Ra is an alkyl group containing 1 to 16 carbon atoms and preferably 1 to 4 carbon atoms or a cycloalkyl group containing 5 to 8 carbon atoms, and Re is an ether group of formula -CH₂ -CH₂ Op- wherein p is a number from 1 to 100, preferably 1 or 2;

##STR6## wherein R'"'"' is Ra, or ReRa, as defined above; and

##STR7## wherein Re and Ra are as defined above.

3. The electrolyte of claim 1 wherein said polymeric material comprises a cured polymerizable or crosslinkable material.

4. The electrolyte of claim 3 wherein said polymeric material is thermally or radiation cured.

5. The electrolyte of claim 4 wherein said polymeric material is radiation cured and includes a repeating unit of any of the following formulae:

##STR8## where R is hydrogen or an alkyl group containing between 1 and 3 carbon atoms and n is an integer ranging between about 3 and about 50.

6. The electrolyte of claim 5 wherein said polymeric material is ethylenically unsaturated.

7. The electrolyte of claim 1 wherein said ionically conductive powder comprises an inorganic powder, a glass powder or a ceramic powder.

8. The electrolyte of claim 7 wherein said solid ionically conductive powder is selected from the group consisting of RbAg₄ I₅, RbCu₁₆ I₇ Cl₁₃, Naβ

-alumina, Ag₆ I₄ WO₄, polycrystalline LiI, Na₃ Zr₂ Si₂ PO₁₂, β

-PbF2, LiI(Al₂ O₃) and B₂ S₃ -Li₂ S-LiI.

9. The electrolyte of claim 1 wherein said electrolyte further comprises an additional curable polymerizable or crosslinkable material.

10. The electrolyte of claim 9 wherein said curable material comprises a nonconductive material.

11. An electrode half element comprising a metal foil having coated thereon the electrolyte of claim 1.

12. The element of claim 11 wherein said electrode is a cathode and said cathode additionally includes an insertion compound and electrically conductive particles.

13. The element of claim 11 wherein said electrode is an anode.

14. The element of claim 13 wherein said metal foil is a lithium foil or a lithium coated foil.

15. A method for forming a composite solid electrolyte comprising the steps of:

forming a mixture of solid ionically conductive powder and a solid ionically conductive polymerizable or crosslinkable material; and

forming a matrix of an ionically conductive polymeric material from said mixture;

wherein said solid ionically conductive powder interpenetrates said matrix.

16. The method according to claim 15 wherein said polymeric material contains a repeating unit selected from the group consisting of:

##STR9## wherein R is hydrogen or a group Ra, -CH₂ ORa, -CH₂ OReRa, -CH₂ N(CH₃)₂, in which Ra is an alkyl group containing 1 to 16 carbon atoms and preferably 1 to 4 carbon atoms or a cycloalkyl group containing 5 to 8 carbon atoms, and Re is an ether group of formula -CH₂ -CH₂ Op- wherein p is a number from 1 to 100, preferably 1 or 2;

##STR10## wherein R'"'"' is Ra, or ReRa, as defined above; and

##STR11## wherein Re and Ra are as defined above.

17. The method according to claim 15 wherein said polymeric material comprises a cured polymerizable or crosslinkable material.

18. The method of claim 17 wherein said polymerizable material includes a repeating unit of any of the following formulae:

##STR12## where R is hydrogen or an alkyl group containing between 1 and 3 carbon atoms and n is an integer ranging between about 3 and about 50.

19. The method of claim 18 wherein said polymerizable material is ethylenically unsaturated.

20. The method of claim 15 wherein said solid ionically conductive powder comprises an inorganic powder, a glass powder or a ceramic powder.

21. The method of claim 20 wherein said solid ionically conductive powder is selected from the group consisting of RbAg₄ I₅, RbCu₁₆ I₇ Cl₁₃, Naβ

-alumina, Ag₆ I₄ WO₄, polycrystalline LiI, Na₃ Zr₂ Si₂ PO₁₂, β

-PbF₂, LiI(Al₂ O₃) and B₂ S₃ -Li₂ S-LiI.

22. A solid state electrochemical cell including a composite solid electrolyte formed by the method of claim 15.

23. A method for forming an electrochemical cell which comprises assembling an anode half element and a cathode half element with a solid composite electrolyte therebetween, said solid composite electrolyte comprising a mixture of a solid ionically conductive powder and an ionically conductive polymeric material.