Functionalized ionic liquid electrolytes for lithium ion batteries

An electrolyte comprising:

• a lithium salt;
• and
• an ionic liquid represented as a compound of Formula:
• wherein
• R is selected from the group consisting of —CH2Si(R″)2[OSi(R″)2]mO Si(R″)3, —(R′)—(OCH2CH2)n—(OR″), a C3-5 cyclic carbonate, a sulfolane, an oxalic borate group, a maleic anhydride group, a succinic anhydride group, and a C1-6 alkyl group substituted with a substituent selected from an isocyanate, sulfone, sulfolane, —OCO2R″, C3-5 cyclic carbonate, or oxalic borate group;
• R′ is a C1-4 alkylene group;
• R″ is an alkyl group;
• R1, R2, and R3 are independently at each occurrence an alkyl, haloalkyl, alkyl substituted with carboxylate, aminoalkyl, cycloalkyl, aryl, heteroaryl, aralkyl, or heteroaralkyl group;
• or two of R1, R2 and R3 join together to form a C4-5 alkylene group;
• R4, R5, R6, R7, and R8 are independently at each occurrence H or an alkyl, haloalkyl, hydroxyalkyl, cycloalkyl, aryl, heteroaryl, aralkyl, or heteroaralkyl group;
• X− is an anion selected from the group consisting of boron tetrafluoride, aluminate, bis(oxalato)borate, difluoro(oxalate)borate, phosphorus hexafluoride, alkyl sulfonate, fluoroalkyl sulfonate, aryl sulfonate, bis(alkylsulfonyl)amide, perchlorate, bis(fluoroalkylsulfonyl)amide, bis(arylsulfonyl)amide, alkyl fluorophosphate, (fluoroalkylsulfonyl)(fluoroalkylcarbonyl)amide, halide, nitrate, nitrite, sulfate, hydrogen sulfate, alkyl sulfate, aryl sulfate, carbonate, bicarbonate, perfluoroalkyl group substituted with carboxylate, phosphate, hydrogen phosphate, dihydrogen phosphate, hypochlorite, an anionic site of a cation-exchange resin, and a mixture of any two or more thereof;
• n is an integer from 1 to 4;
• and
• m is an integer from 0 to 10.