Ion conducting fluoropolymer carbonates for alkali metal ion batteries

Patent metadata

Field	Value
Publication number	US-9755273-B2
Application number	US-201414779460-A
Country	US
Kind code	B2
Filing date	Mar 31, 2014
Priority date	Apr 1, 2013
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Liquid or solid electrolyte compositions are described that comprise a homogeneous solvent system and an alkali metal salt dissolved in said solvent system. The solvent system may comprise a fluoropolymer, having one or two terminal carbonate groups covalently coupled thereto. Batteries containing such electrolyte compositions are also described.

First claim

That which is claimed is:

1. A liquid or solid electrolyte composition, comprising:
(a) a homogeneous solvent system, said solvent system comprising a compound of Formula I:

wherein:
R f is a fluoropolymer having a weight average molecular weight of from 0.2 to 20 Kg/mol; and
R′ and R″ are each independently selected aliphatic, aromatic, or mixed aliphatic and aromatic groups; and
(b) an alkali metal salt dissolved in said solvent system.

2. The composition of claim 1 , wherein said alkali metal salt is a lithium salt.

3. The composition of claim 1 , wherein said alkali metal salt is a sodium salt.

4. The composition of claim 1 , wherein:
said solvent system is included in said composition in an amount of from 70 to 95 percent by weight; and
said salt is included in said composition in an amount of from 5 to 30 percent by weight.

5. A liquid or solid electrolyte composition, comprising:
(a) a homogeneous solvent system, said solvent system comprising a compound of Formula II:

wherein:
R f is a perfluoropolymer having a weight average molecular weight of from 0.2 to 20 Kg/mol; and
R′ is an aliphatic, aromatic, or mixed aliphatic and aromatic group; and
(b) an alkali metal salt dissolved in said solvent system.

6. The composition of claim 5 , wherein R f is a perfluoropolyether.

7. The composition of claim 1 , further comprising an electrode stabilizing agent.

8. The composition of claim 1 , wherein said composition is substantially free of volatile carbonate solvent.

9. The composition of claim 1 , wherein said composition has a T g between −120° C. and −20° C.

10. The composition of claim 1 , wherein said composition does not ignite when heated to a temperature of 235° C. and then contacted to a flame for 15 seconds in a Kohler open cup rapid flash test apparatus.

11. The composition of claim 1 , wherein said composition has an electrochemical stability window of from 3 to 6 volts against Li/Li + .

12. The composition of claim 1 , wherein said fluoropolymer is amorphous.

13. A battery, comprising:
(a) an anode;
(b) a cathode; and
(c) a liquid or solid electrolyte composition operatively associated with said anode and cathode, wherein said electrolyte composition is the composition of claim 1 .

14. The battery of claim 13 , wherein at least one of said anode and said cathode comprises a carbon electrode.

15. A fluoropolymer compound selected from the group consisting of Formula I and Formula II,

wherein:
R f is a perfluoropolyether having a weight average molecular weight of from 0.2 to 20 Kg/mol; and
R′ and R″ are each independently selected from aliphatic, aromatic, or mixed aliphatic and aromatic groups.

16. The fluoropolymer compound of claim 15 , wherein the perfluoropolyether is amorphous.

17. The composition of claim 1 , wherein R f is a perfluoropolymer.

18. The composition of claim 17 , wherein R f is a perfluoropolyether.

19. The composition of claim 5 , wherein:
said solvent system is included in said composition in an amount of from 70 to 95 percent by weight; and
said salt is included in said composition in an amount of from 5 to 30 percent by weight.

20. The composition of claim 5 , wherein said perfluoropolymer is amorphous.

Assignees

• Univ North Carolina Chapel Hill
• Univ California

Inventors

• Desimone Joseph M
• Pandya Ashish
• Wong Dominica
• Balsara Nitash P
• Thelen Jacob
• Devaux Didier

Classifications

• H01M10/0564

  the electrolyte being constituted of organic materials only · CPC title

• H01M12/06

  with one metallic and one gaseous electrode · CPC title

• H01M2300/0082

  Organic polymers · CPC title

• H01M10/0565 Primary

  Polymeric materials, e.g. gel-type or solid-type · CPC title

• H01M10/0569

  characterised by the solvents · CPC title