Organosilicon-containing electrolyte compositions having enhanced electrochemical and thermal stability

1. An electrolyte composition comprising, in combination:

an organosilicon compound, wherein the organosilicon compound has a structure as shown in Formula II:

wherein R 1 and R 3 are the same or different and are independently selected from the group consisting of C 1 to C 6 linear or branched alkyl and halogen;

each R 4 is the same or different and is selected from the group consisting of cyano (—CN), cyanate (—OCN), isocyanate (—NCO), thiocyanate (—SCN) and isothiocyanate (—NCS); and

each subscript “n” is the same or different and is an integer from 1 to 15; and

an imide salt and optionally LiPF 6 ;

wherein when subjected to cyclic voltammetry at a plurality of cycles ranging from about 3V to about 5V and using a cathode current collector comprising aluminum versus Li/Li + electrodes the composition exhibits an oxidative corrosion current of about 0.10 mA/cm 2 or less for a second and subsequent cycles.

2. An electrolyte composition comprising, in combination:

an organosilicon compound, wherein the organosilicon compound has a structure as shown in Formula II:

wherein R 1 and R 3 are the same or different and are independently selected from the group consisting of C 1 to C 6 linear or branched alkyl and halogen;

each R 4 is the same or different and is selected from the group consisting of cyano (—CN), cyanate (—OCN), isocyanate (—NCO), thiocyanate (—SCN) and isothiocyanate (—NCS);

each subscript “n” is the same or different and is an integer from 1 to 15: and

bis(trifluoromethane)sulfonimide lithium salt (LiTFSI); and

lithium bis(oxalato)borate (LiBOB) or LiPF 6 ; and

a carbonate; and

wherein when subjected to cyclic voltammetry at a plurality of cycles ranging from about 3V to about 5V and using a cathode current collector comprising aluminum versus Li/Li + electrodes the composition exhibits an oxidative corrosion current of about 0.10 mA/cm 2 or less for a second and subsequent cycles.

3. An electrolyte composition comprising, in combination:

an organosilicon compound selected from the group consisting of Formula II:

wherein R 1 , R 2 , and R 3 are the same or different and are independently selected from the group consisting of C 1 to C 6 linear or branched alkyl and halogen;

each subscript “n” is the same or different and is an integer from 1 to 15; and

each R 4 is the same or different and is selected from the group consisting of cyano (—CN), cyanate (—OCN), isocyanate (—NCO), thiocyanate (—SCN) and isothiocyanate (—NCS); and

an imide salt and optionally LiPF 6 ;

wherein when subjected to cyclic voltammetry at a plurality of cycles ranging from about 3V to about 5V and using a cathode current collector comprising aluminum versus Li/Li + electrodes the composition exhibits an oxidative corrosion current of about 0.10 mA/cm 2 or less for a second and subsequent cycles; and

wherein the composition exhibits a differential scanning calorimetric (DSC) response onset temperature that is at least 5° C. higher than a corresponding DSC response onset temperature of the organosilicon compound absent the imide salt.

4. The electrolyte composition of claim 3 , wherein imide salt comprises a bis(trifluoromethane)sulfonamide (TFSI) anion.

5. The electrolyte composition of claim 4 , further comprising lithium bis(oxalato)borate (LiBOB) or LiPF 6 .

6. The electrolyte composition of claim 5 , further comprising a carbonate.

7. The electrolyte composition of claim 6 , wherein the carbonate is selected from the group consisting of ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethylmethyl carbonate (EMC), propylene carbonate (PC), and fluoroethylene carbonate (FEC).

8. The electrolyte composition of claim 7 , comprising LiBOB.

9. An electrochemical device comprising an electrolyte composition as recited in any one of claims 1 to 3 and 4 to 8 .