Fire resistant curable solid electrolytes and electrolytic cells produced therefrom

• US 5,455,127 A
• Filed: 03/31/1994
• Issued: 10/03/1995
• Est. Priority Date: 03/31/1994
• Status: Expired due to Term

• Current Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Original Assignee: Valence Technology Incorporated (Lithium Werks B.V.)
• Inventors: Olsen, Ib I., Shackle, Dale R.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Bell, Bruce F.
• Application Number:
  US08/220,797
• Time in Patent Office: 551 Days
• Field of Search: 204/421, 429/191, 429/192, 429/193, 429/199, 429/206, 429/207, 429/213, 429/215
• US Class Current: 429/306
• 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 6/181 with polymeric electrolytes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

This invention is directed to a solid electrolyte containing a polymeric matrix, a salt, a solvent, a viscosifying agent, and a flame retardant, as well as electrolytic cells prepared from such solid electrolytes.

Claims

1. An electrolyte for an electrolytic cell which comprises:

a solid matrix forming monomer;

a salt;

a solvent;

a viscosifying agent; and

a flame retardant.

2. The electrolyte of claim 1, wherein the flame retardant is a flame retardant compound of the formula:

##STR2## wherein each of R¹, R², and R³ is one of an organic aliphatic compound and an aromatic compound.

3. The electrolyte of claim 1, wherein the flame retardant compound comprises trimethyl phosphate, triethyl phosphate, triphenyl phosphate, 2-ethylhexyl diphenyl phosphate, or trimethylene phosphate.

4. The electrolyte of claim 1, having from about 5 to about 25 weight percent salt, based on the total weight of the electrolyte composition.

5. The electrolyte of claim 1, having from about 30 to about 80 weight percent solvent, based on the total weight of the electrolyte composition.

6. The electrolyte of claim 1, having from about 5 to about 30 weight percent solid matrix forming monomer, based on the total weight of the electrolyte composition.

7. The electrolyte of claim 1, having from about 1 to about 15 weight percent viscosifying agent, based on the total weight of the electrolyte composition.

8. The electrolyte of claim 1, having from about 10 to about 40 weight percent flame retardant, based on the total weight of the electrolyte composition.

9. A solid, single-phase, solvent-containing electrolyte which comprises:

a solid polymeric matrix;

a salt;

a solvent;

a viscosifying agent; and

a flame retardant.

10. The solid electrolyte of claim 9, wherein the electrolyte has a thickness of from about 20 to about 250 microns.

11. An electrolytic cell which comprises:

an anode;

a cathode; and

interposed therebetween a solid, solvent-containing electrolyte which comprises;

a solid polymeric matrix;

a salt;

a solvent;

a viscosifying agent; and

a flame retardant.

12. The electrolytic cell of claim 11 wherein the anode is an intercalation based anode comprising carbon.

13. The electrolytic cell of claim 12 wherein the cathode comprises a cathodic material selected from the group consisting of vanadium oxides, lithiated cobalt oxides, lithiated manganese oxides, and mixtures thereof.

14. The electrolytic cell of claim 11 wherein the cathode comprises a cathodic material selected from the group consisting of vanadium oxides, lithiated cobalt oxides, lithiated manganese oxides, and mixtures thereof.

15. A process for preparing a solid electrolyte for an electrolytic cell which comprises:

(a) providing an electrolyte composition comprising;

a solid matrix forming monomer,

a salt,

a solvent,

a viscosifying agent, and

a flame retardant; and

(b) curing said electrolyte composition to provide a solid electrolyte.

16. A process for preparing a solid electrolyte for an electrolytic cell which comprises:

(a) polymerizing a solid matrix forming monomer to form a solid polymeric matrix;

(b) dissolving said solid polymeric matrix in a suitable volatile solvent;

(c) adding a salt, an electrolyte solvent, a viscosifying agent, and a flame retardant to form an electrolyte composition; and

(d) removing said volatile solvent and curing said electrolyte composition to provide a solid electrolyte.

17. A process for preparing an electrolytic cell which comprises:

(a) providing an anode;

(b) providing a cathode;

(c) interposing between surfaces of the cathode and the anode an electrolyte composition comprising;

a solid matrix forming monomer,

a salt,

a solvent,

a viscosifying agent, and

a flame retardant; and

(d) curing said electrolyte composition to provide a solid electrolyte bonded to the surfaces of both the anode and cathode.

18. The process of claim 17 wherein the anode is an intercalation based anode comprising carbon.

19. The process of claim 18 wherein the cathode comprises a cathodic material selected from the group consisting of vanadium oxides, lithiated cobalt oxides, lithiated manganese oxides, and mixtures thereof.

20. The process of claim 17 wherein the cathode comprises a cathodic material selected from the group consisting of vanadium oxides, lithiated cobalt oxides, lithiated manganese oxides, and mixtures thereof.