Gel polymer electrolyte including crosslinked network of poss and peg, ionic liquid, and lithium salt, lithium battery including the same, and process of preparing the same

Patent metadata

Field	Value
Publication number	US-11848417-B2
Application number	US-202117246681-A
Country	US
Kind code	B2
Filing date	May 2, 2021
Priority date	May 1, 2020
Publication date	Dec 19, 2023
Grant date	Dec 19, 2023

Abstract

Ionic liquid N-methyl-N-propyl-pyrrolidinium bis(fluorosulfonyl)imide (Pyr13FSI) was introduced into a hybrid network to obtain a series of gel polymer electrolytes (GPEs). Mechanical and electrochemical properties of the GPEs were tuned through controlling the network structure and ionic liquid contents, and ionic conductivity higher than 1 mS cm−1 at room temperature was achieved. The newly developed GPEs are flame-retardant and show excellent thermal and electrochemical stability as well as ultra-stability with lithium metal anode. Symmetrical lithium cells with the GPEs exhibit a stable cycling over 6800 h at a current density of 0.1 mA cm−2 and stable lithium stripping-plating at 1 mA cm−2, the highest current density reported for ionic liquid-based GPEs. Moreover, Li/LiFePO4 batteries with the obtained GPEs exhibit desirable cycling stability and rate performance over a wide temperature range from 0° C. to 90° C.

First claim

What is claimed is:

1. A lithium gel polymer electrolyte composition comprising:
a crosslinked network formed by a cross-linking reaction comprising reacting an inorganic polyhedral oligomeric silsesquioxane with either:
a) a functionalized poly(ethylene glycol), or
b) a functionalized poly(ethylene oxide);

an ionic liquid that is N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide; and
one or more lithium salts.

2. The composition of claim 1 , wherein the inorganic polyhedral oligomeric silsesquioxane has a structure:

wherein each R group is independently selected from the group consisting of hydrogen, hydrocarbyl, reactive functional groups and functionalized hydrocarbyl groups and at least one of the R groups contains a functional group suitable for the cross-linking reaction.

3. The composition of claim 1 , wherein the inorganic polyhedral oligomeric silsesquioxane is selected from the group consisting of octakis(3-glycidyloxypropyldimethylsiloxy)octasilsesquioxane, epoxycyclohexylethyl polysilsesquioxane, glycidyl polyhedral oligomeric silsesquioxane, and octa epoxycyclohexyldimethylsilyl polyhedral oligomeric silsesquioxane.

4. The composition of claim 1 , wherein the ionic liquid is present in an amount of from about 1 wt. % to about 90 wt. %, based on a total weight of the lithium gel polymer electrolyte.

5. The composition of claim 1 , wherein the lithium salt is present in an amount of from 50 wt % to about 90 wt %, based on a total weight of the lithium gel polymer electrolyte.

6. The composition of claim 1 ,
wherein the lithium salt is a lithium salt with an anion of bis(trifluoromethane)sulfonamide, hexafluoroarsenate, hexafluorophosphate, perchlorate, tetrafluoroborate, tris(pentafluoroethyl)trifluorophosphate, trifluoromethanesulfonate, bis(fluorosulfonyl)imide, cyclo-difluoromethane-1,1-bis(sulfonyl)imide, cyclo-hexafluoropropane-1,1-bis(sulfonyl)imide, bis(perfluoroethanesulfonyl)imide, bis(oxalate)borate, difluoro(oxalato)borate, tetracyanoborate, dicyanotriazolate, dicyano-trifluoromethyl-imidazole, and dicyano-pentafluoroethyl-imidazole.

7. The composition of claim 1 , further comprising a solvent selected from the group consisting of tetrahydrofuran, diethyl ether, acetonitrile, ethyl acetate, and methyl acetate.

8. The composition of claim 1 , wherein an overall ionic conductivity is 1 mS cm −1 or greater at 20° C.

9. The composition of claim 1 , wherein the polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene oxide) and the functionalized poly(ethylene oxide) is an amine-terminated diterminal functionalized (polyethylene oxide).

10. The composition of claim 1 , where the inorganic polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene glycol) in a molar ratio of from about 1:100 to about 10:1.

11. The composition of claim 1 , wherein the inorganic polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene glycol) in a molar ratio of from about 1:4 to about 1:2.

12. The composition of claim 1 , wherein the polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene glycol) and the functionalized poly(ethylene glycol) is an amine-terminated diterminal functionalized poly(ethylene glycol).

13. The composition of claim 12 , wherein the amine-terminated poly(ethylene glycol), has a number average molecular weight of from about 2,000 g/mol to about 6,000 g/mol.

14. A battery comprising the composition of claim 8 and a metal anode.

15. The battery of claim 14 , wherein the metal anode is lithium.

16. The battery of claim 14 , wherein the battery delivers stable cycling performance over 6800 hours at a current density of 0.1 mA cm −2 and a charge-discharge cycle takes a total of about 3 hours, or
the battery delivers a stable cycling performance over at least 2250 charge-discharge steps, at a current density of 0.1 mA cm −2 , and
wherein stable cycling performance means having a repeatable voltage profile with no insubstantial noise attributable to pulverization, delamination, corrosion, or other side reactions and one cycle equals 1 charge plus 1 discharge.

17. A process of preparing the lithium gel polymer electrolyte of claim 1 , comprising reacting the inorganic polyhedral oligomeric silsesquioxane with either:
a) the functionalized poly(ethylene glycol); or
b) the functionalized poly(ethylene oxide),

in a presence of the ionic liquid, and the one or more lithium salts to form the crosslinked network in a single-step polymerization process.

18. The process of claim 17 , wherein the polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene glycol) and the functionalized poly(ethylene glycol) is an amine-terminated diterminal functionalized poly(ethylene glycol).

19. The process of claim 17 , wherein the polyhedral oligomeric silsesquioxane is reacted with the functionalized poly(ethylene oxide) and the functionalized poly(ethylene oxide) is an amine-terminated diterminal functionalized poly(ethylene oxide).

Assignees

• Li Xiaowei
• Zheng Yongwei
• Li Christopher
• Univ Drexel

Inventors

• Li Xiaowei
• Zheng Yongwei
• Li Christopher

Classifications

• H01M10/0565 Primary

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

• C08G65/336 Primary

  containing silicon · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/0567

  characterised by the additives · CPC title

• H01M10/4235

  Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence) · CPC title