Polymer Solid Electrolyte for Flexible Batteries

• US 20100255383A1
• Filed: 03/01/2010
• Published: 10/07/2010
• Est. Priority Date: 02/27/2009
• Status: Active Grant

• Current Assignee: University of Maryland, College Park
• Original Assignee: University of Maryland, College Park
• Inventors: Ghosh, Ayan, Kofinas, Peter
• Granted Patent: US 9,252,456 B2
• Time in Patent Office: Days
• US Class Current: 429/317
• CPC Class Codes: C08J 2335/02 Characterised by the use of homopolymers or copolymers of esters C08J2335/06, C08J2335/08 take precedence
• CPC Class Codes: C08J 2371/12 Polyphenylene oxides
• CPC Class Codes: C08J 5/2268 based on macromolecular compounds obtained by reactions involving unsaturated carbon-to-carbon bonds, and by reactions not involving this type of bond
• CPC Class Codes: H01M 10/0565 Polymeric materials, e.g. gel-type or solid-type
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 6/181 with polymeric electrolytes
• CPC Class Codes: H01M 6/188 Processes of manufacture
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A flexible polymer solid electrolyte material useful in battery technology is described. The flexible solid electrolyte comprises a first block that has the ability to solvate alkali metal salts. The flexible solid electrolyte comprises a second block that has the ability to incorporate lithium ions within microphase separated spherical domains, wherein the lithium ions are from a secondary lithium source. The flexible solid electrolyte further comprises a second lithium salt.

Claims

1. A solid polymer electrolyte comprising:

a) a lithium salt of a diblock copolymer wherein the diblock copolymer comprises a polyether block and an acrylate block; and

b) a second lithium salt.

2. The solid polymer electrolyte of claim 1, wherein the polyether block is polyethylene oxide.

3. The solid polymer electrolyte of claim 1, wherein the acrylate block is methylmethacrylate.

4. The solid polymer electrolyte of claim 1, wherein the solid polymer electrolyte has reduced crystallinity compared to PEO of similar molecular weight.

5. The solid polymer electrolyte of claim 1, wherein the acrylate block is a random copolymer.

6. The solid polymer electrolyte of claim 1, wherein the diblock copolymer is a PEO-b-PMMA block copolymer.

7. The solid polymer electrolyte of claim 6, wherein the molecular weight ratio of PEO to PMMA is between about 4:

1 to about 10;

1.

8. The solid polymer electrolyte of claim 1, wherein the lithium salt of the diblock copolymer is a lithium salt of an acrylic acid.

9. The solid polymer electrolyte of claim 8, wherein the lithium salt of the diblock copolymer is a lithium salt of methacrylic acid.

10. The solid polymer electrolyte of claim 1, wherein the lithium salt of a diblock copolymer is PEO-b-(PMMA-ran-PMAALi).

11. The solid polymer electrolyte of claim 1, wherein the second lithium salt is selected from the group consisting of LiPF₆, LiBF₄, LiSbF₆, LiAsF₆, LiClO₄, LiCF₃SO₃, LiC₄F₉SO₃, LiAlO₄, LiAlCl₄, and lithium bis(oxalato)borate.

12. The solid polymer electrolyte of claim 11, wherein the second lithium salt is lithium bis(oxalato)borate.

13. The solid polymer electrolyte of claim 11, wherein the ratio of the diblock copolymer to the second lithium salt is between about 65% to about 95% ethylene oxide unit to between about 35% to about 5% second lithium salt.

14. The solid polymer electrolyte of claim 11, wherein the ratio of the diblock copolymer to the second lithium salt is about 75% ethylene oxide unit to about 25% second lithium salt.

15. The solid polymer electrolyte of claim 11, wherein the ratio of the diblock copolymer to the second lithium salt is about 80% ethylene oxide unit to about 20% second lithium salt.

16. The solid polymer electrolyte of claim 1, wherein the lithium ions of the lithium salt of the diblock copolymer are incorporated within the microphase separated spherical domains of the acrylate block.

18. A battery comprising the solid polymer electrolyte of claim 1.

17. A solid polymer electrolyte, comprising a polyethylene oxide polymer block, a methylmethacrylate polymer block comprising a lithium salt of methacrylic acid, and lithium bis(oxalato)borate.

19. A method of producing a solid polymer electrolyte comprising:

(a) hydrolyzing a solution of a diblock copolymer comprising a polyether block and an acrylate ester block, with lithium hydroxide in an organic solvent to give a diblock copolymer salt;

(b) drying the diblock copolymer salt produced by a); and

(c) dissolving said diblock copolymer salt in an organic solvent and adding a second lithium salt to give a polymer solution.

20. The method of claim 19, wherein the solution in a) is produced by adding a mixture of 1,4-dioxane and methanol.

21. The method of claim 19, further comprising:

d) casting the polymer solution of c) into an apparatus containing a substrate; and

e) drying the polymer solution to produce a polymer electrolyte film.