Fluoro-substituted ethers and compositions

Patent metadata

Field	Value
Publication number	US-2018076485-A1
Application number	US-201615265603-A
Country	US
Kind code	A1
Filing date	Sep 14, 2016
Priority date	Sep 14, 2016
Publication date	Mar 15, 2018
Grant date	—

Abstract

Described herein are fluoro-substituted ethers of Formula (I):

wherein R 1 is a fluoro-substituted C 2 -C 6 alkyl group; R 2 is a C 2 -C 6 alkyl group or a fluoro-substituted C 2 -C 6 alkyl group; each R 3 independently is H, F, methyl, or fluoro-substituted methyl; and n is 0, 1, 2, 3, or 4. The fluoro-substituted ether compounds are useful as solvents for lithium containing electrolytes in lithium batteries, particularly lithium-sulfur batteries.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1 . An electrolyte composition for a lithium battery comprising a lithium salt dissolved in a solvent comprising one or more fluoro-substituted ethers of Formula (I):

wherein R 1 is a fluoro-substituted C 2 -C 6 alkyl group; R 2 is a C 2 -C 6 alkyl group or a fluoro-substituted C 2 -C 6 alkyl group; each R 3 independently is H, F, methyl, or fluoro-substituted methyl; and n is 0, 1, 2, 3, or 4.

2 . The electrolyte composition of claim 1 , wherein R 2 is a fluoro-substituted C 2 -C 6 alkyl group.

3 . The electrolyte composition of claim 1 , wherein R 2 is a C 2 -C 6 alkyl group.

4 . The electrolyte composition of claim 1 , wherein R 1 and/or R 2 is a fluoro-substituted C 2 -C 6 alkyl group comprising at least one methylene (CH 2 ) or methine (CH) group.

5 . The electrolyte composition of claim 1 , wherein at least one R 3 is H.

6 . The electrolyte composition of claim 1 , wherein each R 3 is H.

7 . The electrolyte composition of claim 1 , wherein the solvent further comprises a co-solvent selected from one or more of an ether, a carbonate ester, a nitrile, a sulfoxide, and a sulfone.

8 . The electrolyte composition of claim 7 , wherein the co-solvent comprises one or more ether selected from dioxolane, tetrahydrofuran, dimethoxyethane, diglyme, triglyme, and tetraglyme.

9 . The electrolyte composition of claim 7 , wherein the co-solvent comprises one or more carbonate ester selected from ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate.

10 . The electrolyte composition of claim 7 , wherein the co-solvent and the compound of Formula (I) are present in the solvent mixture in a respective volume ratio in the range of about 1:9 to about 9:1.

11 . The electrolyte composition of claim 1 , wherein the fluoro-substituted ether of Formula (I) comprises one or more of:
1,1,1,11,11,11-hexafluoro-3,6,9-trioxaundecane, 1,1,1,14,14,14-hexafluoro-3,6,9,12-tetraoxatetradecane, 1,1,1,17,17,17-hexafluoro-3,6,9,12,15-pentaoxaheptadecane, 1,1,1-trifluoro-3,6,9-trioxadecane, and 1,1,1,2,2,12,12,13,13,13-decafluoro-4,7,10-trioxatridecane.

12 . The electrolyte composition of claim 1 , wherein the lithium salt comprises one or more of lithium bis(trifluoromethane)sulfonimidate (LiTFSI), lithium 2-trifluoromethyl-4, 5-dicyanoimidazolate (LiTDI), lithium 4,5-dicyano-1,2,3-triazolate (LiTDI), lithium trifluoromethanesulfonate (LiTf), lithium perchlorate (LiClO 4 ), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium tetrafluoroborate (LiBF 4 ), lithium hexafluorophosphate (LiPF 6 ), lithium thiocyanate (LiSCN), lithium bis(fluorosulfonyl)imidate (LIFSI), lithium bis(pentafluoroethylsulfonyl)imidate (LBETI), lithium tetracyanoborate (LiB(CN) 4 ), and lithium nitrate.

13 . The electrolyte composition of claim 1 , wherein the lithium salt comprises lithium bis(trifluoromethane)sulfonimidate.

14 . The electrolyte composition of claim 1 , wherein the lithium salt is present in the solvent at a concentration in the range of about 0.1 to about 1.2 molar.

15 . A fluoro-substituted ether of Formula (I):

wherein R 1 is a fluoro-substituted C 2 -C 6 alkyl group; R 2 is a C 2 -C 4 alkyl group or a fluoro-substituted C 2 -C 6 alkyl group; each R 3 independently is H, F, methyl, or fluoro-substituted methyl; and n is 1, 2, 3, or 4.

16 . The fluoro-substituted ether of claim 1 , wherein R 2 is a fluoro-substituted C 2 -C 6 alkyl group.

17 . The fluoro-substituted ether of claim 1 , wherein R 2 is a C 2 -C 6 alkyl group.

18 . The fluoro-substituted ether of claim 1 , wherein R 1 and/or R 2 is a fluoro-substituted C 2 -C 6 alkyl group comprising at least one methylene (CH 2 ) or methine (CH) group.

19 . The fluoro-substituted ethers of claim 1 , wherein at least one R 3 is H.

20 . The fluoro-substituted ethers of claim 1 , wherein each R 3 is H.

21 . A lithium-sulfur battery comprising a sulfur-containing positive electrode, a lithium-containing negative electrode, and the electrolyte of claim 1 therebetween.

Assignees

• Uchicago Argonne Llc

Inventors

• Zhang Zhengcheng
• Su Chi Cheung

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/623

  fluorinated polymers · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M2300/0034

  Fluorinated solvents · CPC title