Electrolyte composition

Patent metadata

Field	Value
Publication number	US-11522220-B2
Application number	US-201816649753-A
Country	US
Kind code	B2
Filing date	Nov 2, 2018
Priority date	Nov 2, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

An electrolyte composition comprising (i) a block copolymer, (ii) an organic electrolyte (e.g. an ionic liquid), and (iii) a lithium salt, wherein the block copolymer comprises a non-ionic block and an ionic block, the non-ionic block comprising polymerised residues of hydrophobic monomers, and the ionic block comprising polymerised monomer residues having covalently coupled thereto (a) a pendant organic ionic liquid cation, the pendant organic ionic liquid cation having a counter anion, (b) a pendant anionic moiety, the pendant anionic moiety having a counter cation, or (c) a combination thereof, and the electrolyte composition has at least two glass transition temperature (Tg) values.

First claim

The claims defining the invention are as follows:

1. An electrolyte composition comprising:
i) a block copolymer,
ii) an organic electrolyte, and
iii) a lithium salt,
wherein the block copolymer comprises a non-ionic block and an ionic block, the non-ionic block comprising polymerized residues of hydrophobic monomers, and the ionic block comprising polymerized monomer residues having covalently coupled thereto (a) a pendant organic ionic liquid cation, the pendant organic ionic liquid cation having a counter anion, (b) a pendant anionic moiety, the pendant anionic moiety having a counter cation, or (c) a combination thereof, and
the electrolyte composition has at least two glass transition temperature (Tg) values.

2. The electrolyte composition of claim 1 , wherein the molar weight of the non-ionic block combined with the ionic block is less than 40,000 g/mol.

3. The electrolyte composition of claim 1 , wherein the lithium salt is present in an amount of at least 11 wt. % relative to the total weight of the electrolyte composition.

4. The electrolyte composition of claim 1 , wherein the organic electrolyte is present in an amount of less than 55.0 wt. % relative to the total weight of the electrolyte composition.

5. The electrolyte composition of claim 1 , wherein the non-ionic block comprises a repeating unit having either of the following structures (I) and (II):

where R 1 , R 2 , R 3 , and R 4 are each independently H or C 1-6 alkyl.

6. The electrolyte composition of claim 1 , wherein the non-ionic block comprises polymerized residues of hydrophobic monomers derived from styrene or styrene derivatives, indene or indene derivatives, vinylpyridine or vinylpyridine derivatives, methyl methacrylate or methacrylate derivatives, or a combination thereof.

7. The electrolyte composition of claim 6 , wherein the non-ionic block comprises polymerized residues of hydrophobic monomers derived from α-methylstyrene, methylstyrene, chlorostyrene, hydroxystyrene, vinylbenzyl chloride, methylindene, ethylindene, trimethylindene, vinylmethylpyridine, vinylbutylpyridine, vinylquinioline, vinylacrydine, hydroxyethyl methacrylate, dimethylamino-ethyl methacrylate, vinylcarbaxole, or a combination thereof.

8. The electrolyte composition of claim 1 , wherein the ionic block comprises a repeating unit having the following structure (III):

where R 5 , R 6 , R 7 , and R 8 are each independently H or optionally substituted C 1-12 alkyl, and n has a value in a range from 0 to about 20, or from 0 to about 10, or from 0 to about 5.

9. The electrolyte composition of claim 1 , wherein the ionic block comprises polymerized monomer residues selected from acryloyl-imidazolium, acryloyl-pyrrolidinium, acryloyl-pyridinium, vinyl-imidazolium, vinyl-pyrrolidinium, vinyl-pyridinium, styrene-imidazolium, styrene-pyrrolidinium, styrene-pyridinium, and a combination thereof.

10. The electrolyte composition of claim 1 , wherein the pendant organic ionic liquid cation comprises 1-butyl(propyl)-1-methylpyrrolidinium (C 4 C 3 mpyr), N-methyl-N-propylpyrrolidinium (C 3 mpyr), N-butyl-N-methylpyrrolidinium (C 4 mPyr), 1-ethyl-3-methylimidazolium (C 2 mim), 1-propyl-3-methylimidazolium (C 3 mim), 1-butyl-3-methylimidazolium (C 4 mim), 1-hexyl-3-methylimidazolium (C 6 mim), 1-octyl-3-methylimidazolium (C 8 mim), 1-dodecyl-3-methylimidazolium (C 12 mim), 1-hexadecyl-3-methylimidazolium (C 16 mim), 1,2-dimethyl-3-butylimidazolium(C 4 (2-C 1 )mim), 1-(3-aminopropyl)-3-methylimidazolium ((3-aminopropyl)mim), 1,2-dimethyl-3-(3-hydroxypropyl)imidazolium ((C 2 —OH)), N-ethyl-tris(2-(2-methoxyethoxy)ethyl) ethane ammonium (N 2(2o2o1)3 ), Trihexyl(tetradecyl)phosphonium (P 66614 ), Diethyl(methyl)(isobutyl)phosphonium (P 122i4 ), Triisobutyl(methyl)phosphonium (P 1i4i4i4 ), Triethyl(methyl)phosphonium (P 1222 ), Trimethyl(isobutyl)phosphonium (P 111i4 ), or a combination thereof.

11. The electrolyte composition of claim 1 , wherein the counter anion of the pendant organic ionic liquid cation is selected from alkyl phosphate, biscarbonate, bistriflimide, carbonate, chlorate, formate, glycolate, perchlorate, hexasubstituted phosphate, tetra-substituted borate, optionally fluorinated C 1-4 alkyl-BF3 − , tosylate, triflate, and a combination thereof.

12. The electrolyte composition of claim 11 , wherein the counter anion of the pendant organic ionic liquid cation is selected from bis(trifluoromethanesulfonyl)imide (TFSI), triflate (OTf), tetrafluoroborate (BF 4 ), hexafluorophosphate (PF 6 ), bis(fluorosulfonyl)imide (FSI), fluorosulfonyl-(trifluoromethanesulfonyl) imide (FTFSI), and a combination thereof.

13. The electrolyte composition of claim 1 , wherein the pendant anionic moiety comprises derivatives of bis(trifluoromethanesulfonyl)imide (TFSI), triflate (OTf), Tetrafluoroborate (BF 4 ), hexafluorophosphate (PF 6 ), bis(fluorosulfonyl)imide (FSI), fluorosulfonyl-(trifluoromethanesulfonyl) imide (FTFSI), or a combination thereof.

14. The electrolyte composition of claim 1 , having a (organic electrolyte:ionic block) molar fraction of between about 0.01 and about 1.

15. The electrolyte composition of claim 1 , having a (lithium salt:ionic block) molar fraction of between about 0.01 and about 15.

16. The electrolyte composition of claim 1 , wherein the organic electrolyte comprises an organic ionic liquid having a cation and a counter anion, the organic ionic liquid not being covalently coupled to the block copolymer.

17. The electrolyte composition of claim 16 , wherein the cation of the organic ionic liquid that is not covalently coupled to the block copolymer is selected from an ammonium cation, a pyridinium cation, a pyrrolidinium cation, a phosphonium cation, and a combination thereof.

18. The electrolyte composition of claim 16 , wherein the cation of the organic ionic liquid that is not covalently coupled to the block copolymer is selected from 1-butyl(propyl)-1-methylpyrrolidinium (C 4 C 3 mpyr), N-methyl-N-propylpyrrolidinium (C 3 mpyr), N-butyl-N-methylpyrrolidinium (C 4 mPyr), N-ethyl-tris(2-(2-methoxyethoxy)ethyl) ethane ammonium (N 2(2o2o1)3 ), Trihexyl(tetradecyl)phosphonium (P 66614 ), Diethyl(methyl)(isobutyl)phosphonium (P 122i4 ), Triisobutyl(methyl)phosphonium (P 1i4i4i4 ), Triethyl(methyl)phosphonium (P 1222 ), Trimethyl(isobutyl)phosphonium (P 111i4 ), and a combination thereof.

19. The electrolyte composition of claim 16 , wherein the anion of the organic ionic liquid that is not covalently coupled to the block copolymer is selected from aqueous or anhydrous alkyl phosphate, biscarbonate, bistriflimide, carbonate, chlorate, formate, glycolate, perchlorate, hexasubstituted phosphate, tetra-substituted borate, optionally fluorinated C 1-4 alkyl-BF 3 − , tosylate, triflate, and a combination thereof.

20. The electrolyte composition of claim 1 , wherein the block copolymer is a tri-block copolymer.

21. A lithium-based electrochemical cell comprising a negative electrode and an electrolyte composition as defined in claim 1 .

22. The lithium-based electrochemical cell of claim 21 , wherein the negative electrode comprises expanded graphite, hard carbon, coke, carbon black, glassy carbon, or a combination thereof.

23. The lithium-based electrochemical cell of claim 21 , the cell ha

Assignees

• Commw Scient Ind Res Org

Inventors

• Chiefari John
• Barlow Kristine
• Goujon Nicolas
• Hao Xiaojuan
• Forsyth Maria
• Howlett Patrick C

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M10/052

  Li-accumulators · CPC title

• C08K5/19

  Quaternary ammonium compounds · CPC title

• C08K5/3432

  Six-membered rings · CPC title

• H01M10/0569

  characterised by the solvents · CPC title