Functional organic salt for lithium-ion batteries
An electrolyte for a lithium-ion electrochemical cell comprises a non-aqueous solution of a lithium salt and a redox shuttle salt compound in a non-aqueous solvent, wherein the redox shuttle compound comprises an amino-substituted cyclopropenium salt of Formula (I) as described herein.
1. An electrolyte for a lithium-ion electrochemical cell comprising a non-aqueous solution of a lithium salt and a redox shuttle salt in an organic solvent; wherein the redox shuttle salt comprises a compound of Formula (I):
wherein X ⊖ is an anion selected from the group consisting of a halide, and bis(trifluoromethanesulfonyl)imidate, tetrafluoroborate, hexafluorophosphate, and an anion of Formula (II):
Z is selected from the group consisting of alkylsulfonyl, alkylcarbonyl, fluorinated-alkylsulfonyl, and fluorinated-alkylcarbonyl;
R and R′ are independently selected from the group consisting of C 1 to C 8 alkyl, aryl, alkylaryl, and poly(alkylene glycol) groups; and
the alkyl, aryl, arylalkyl and alkylaryl groups optionally are substituted by one of more substituent selected from halogen, hydroxyl, alkoxy, alkylsulfonyl, and arylsulfonyl; and wherein the compound of Formula (I) is present in the organic solvent at a concentration in the range of about 0.005 M to about 0.5 M.
2. The electrolyte of claim 1 , wherein R and R′ are ethyl.
3. The electrolyte of claim 1 , wherein X ⊖ is a halide.
4. The electrolyte of claim 1 , wherein X ⊖ is chloride.
5. The electrolyte of claim 1 , wherein X ⊖ is a sulfonimidate anion.
6. The electrolyte of claim 1 , wherein X ⊖ is an anion of Formula (II):
wherein Z is selected from the group consisting of alkylsulfonyl, alkylcarbonyl, fluorinated-alkyl sulfonyl, and fluorinated-alkylcarbonyl.
7. The electrolyte of claim 1 , wherein X ⊖ is bis(trifluoromethanesulfonyl)imidate anion.
8. The electrolyte of claim 1 , wherein the lithium salt comprises one or more salt selected from the group consisting of lithium bis(trifluoromethanesulfonyl)imidate (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.
9. The electrolyte of claim 1 , wherein the lithium salt is present in the electrolyte at a concentration in the range of about 0.1 M to about 3 M.
10. The electrolyte of claim 1 , wherein the non-aqueous solvent comprises one or more solvent selected from the group consisting of an ether, a carbonate ester, a nitrile, a sulfoxide, a sulfone, a fluoro-substituted linear dialkyl carbonate, a fluoro-substituted cyclic alkylene carbonate, a fluoro-substituted sulfolane, and a fluoro-substituted sulfone.
11. The electrolyte of claim 1 , wherein the non-aqueous solvent comprises one or more carbonate esters selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate.
12. The electrolyte of claim 1 , wherein the non-aqueous solvent comprises ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in an EC:EMC ratio of about 3:7 (v:v).
13. The electrolyte of claim 12 , wherein the lithium salt comprises about 1 to 1.5 M LiPF 6 and the compound of Formula (I) comprises about 0.3 to 0.5 M CP-Cl.
14. The electrolyte of claim 12 , wherein the lithium salt comprises about 1 to 1.5 M LiPF 6 and the compound of Formula (I) comprises about 0.3 to 0.5 M CP-TFSI.
15. An electrochemical cell comprising an anode, a cathode, a lithium ion-porous membrane between the anode and the cathode, and the electrolyte of claim 1 contacting the anode, the cathode, and the membrane.
16. A battery comprising a plurality of electrochemical cells of claim 15 electrically connected together in series, in parallel, or in both series and parallel.
17. An electrolyte for a lithium-ion electrochemical cell comprising a non-aqueous solution of a lithium salt and a redox shuttle salt in an organic solvent wherein the redox shuttle salt comprises tris(diethylamino)cyclopropenium chloride (CP-Cl), which has the formula:
and wherein the concentration of the redox shuttle salt is about 0.3 to 0.5 M; the non-aqueous solvent comprises one or more carbonate esters selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate; and the lithium salt comprises about 1 to 1.5 M LiPF 6 .
18. The electrolyte of claim 17 , wherein the non-aqueous solvent comprises ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in an EC:EMC ratio of about 3:7 (v:v).
19. The electrolyte of claim 9 , wherein the non-aqueous solvent comprises ethylene carbonate (EC) and ethyl methyl carbonate (EMC) in an EC:EMC ratio of about 3:7 (v:v).
20. An electrolyte for a lithium-ion electrochemical cell comprising a non-aqueous solution of a lithium salt and a redox shuttle salt in an organic solvent; wherein the redox shuttle salt comprises tris(diethylamino)cyclopropenium bis(trifluoromethanesulfonyl)imidate (CP-TSFI), which has the formula:
and wherein the concentration of the redox shuttle salt is about 0.3 to 0.5 M; the non-aqueous solvent comprises one or more carbonate esters selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethylmethyl carbonate; and the lithium salt comprises about 1 to 1.5 M LiPF 6 .