Nonaqueous electrolyte compositions for lithium-ion battery

1. A lithium-ion battery, comprising a positive electrode plate, a negative electrode plate, a separator, and a nonaqueous electrolyte, wherein the positive electrode plate comprises Li 1+x Ni a Co b Me (1−a−b) O 2−c Y c , wherein −0.1≤x≤0.2, 0.8≤a<1, 0<b<1, 0<(1−a−b)<1, 0≤c<1, Me is selected from one or more of Mn, Al, Mg, Zn, Ga, Ba, Fe, Cr, Sn, V, Sc, Ti, and Zr, and Y is selected from one or more of F, Cl, and Br;

the nonaqueous electrolyte comprises a nonaqueous solvent and a lithium salt, wherein the nonaqueous solvent comprises a carbonate solvent and a high oxidation potential solvent, and the high oxidation potential solvent comprises two compounds respectively represented by formula I and formula II;

in formula I, R 1 and R 2 are independently selected from unsubstituted, partially halogenated, or fully halogenated alkyl groups having 1 to 5 carbon atoms, and at least one of R 1 and R 2 is a partially halogenated or fully halogenated alkyl group having 1 to 5 carbon atoms; and

in formula II, R 3 is selected from partially halogenated or fully halogenated alkylidene groups having 1 to 6 carbon atoms, wherein

a halogen atom is selected from one or more of F, Cl, Br, and I; and

wherein the high oxidation potential solvent includes both the compound represented by formula I and the compound represented by formula II;

wherein based on a total weight of the nonaqueous solvent, a weight percentage of the two compounds respectively represented by formula I and formula II is greater than 10%.

2. The lithium-ion battery according to claim 1 , wherein

the carbonate solvent is selected from one or more of cyclic carbonate and linear carbonate.

3. The lithium-ion battery according to claim 2 , wherein

based on a total weight of the nonaqueous solvent, a weight percentage of the cyclic carbonate is 0 to 10%.

4. The lithium-ion battery according to claim 2 , wherein

a weight ratio of the linear carbonate to the cyclic carbonate is 80:1 to 1:1.

5. The lithium-ion battery according to claim 1 , wherein

the carbonate solvent is selected from linear carbonate or a mixture of linear carbonate and cyclic carbonate.

6. The lithium-ion battery according to claim 1 , wherein

in formula I, R 1 and R 2 are independently selected from unsubstituted, partially fluorinated or fully fluorinated alkyl groups having 1 to 5 carbon atoms, and at least one of R 1 and R 2 is a partially fluorinated or fully fluorinated alkyl group having 1 to 5 carbon atoms; and

in formula II, R 3 is selected from partially fluorinated or fully fluorinated alkylidene groups having 1 to 6 carbon atoms.

7. The lithium-ion battery according to claim 1 , wherein

in formula I, R 1 and R 2 are independently selected from —CH 3 , —CF 3 , —CH 2 CH 3 , —CF 2 CH 3 , —CH 2 CF 3 , —CF 2 CF 3 , —CH 2 CH 2 CH 3 , —CF 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , —CH 2 CF 2 CF 3 , —CF 2 CH 2 CF 3 , —CF 2 CF 2 CH 3 , and —CF 2 CF 2 CF 3 , and at least one of R 1 and R 2 is —CF 3 , —CF 2 CH 3 , —CH 2 CF 3 , —CF 2 CF 3 , —CF 2 CH 2 CH 3 , —CH 2 CH 2 CF 3 , —CH 2 CF 2 CF 3 , —CF 2 CH 2 CF 3 , —CF 2 CF 2 CH 3 , or —CF 2 CF 2 CF 3 ; and

in formula II, R 3 is selected from —CHFCH 2 CH 2 CH 2 —, —CF 2 CH 2 CH 2 CH 2 —, —CF 2 CH 2 CH 2 CHF—, —CF 2 CH 2 CH 2 CF 2 —, —CH 2 CH 2 CHFCH 2 —, —CH 2 CHFCHFCH 2 —, —CH 2 CH 2 CH(CF 3 )CH 2 —, —CF 2 CH 2 CH 2 CH 2 CH 2 —, —CF 2 CH 2 CH 2 CH 2 CF 2 —, —CH 2 CH 2 CH 2 CHFCH 2 —, —CH 2 CHFCH 2 CHFCH 2 —, —CH 2 CHFCH 2 CHFCHF—, —CH 2 CH 2 CH 2 CH 2 CHF—, —CH 2 CH 2 CH 2 CH(CF 3 )CH 2 —, —CF 2 CH 2 CH 2 CH 2 CH 2 CH 2 —, —CH 2 CH 2 CH 2 CH 2 CHFCH 2 —, —CH 2 CHFCH 2 CH 2 CHFCH 2 —, —CF 2 CH 2 CH 2 CH 2 CH 2 CF 2 —, —CH 2 CH 2 CH(CH 3 )CH 2 CHFCH 2 —, and —CH 2 CH 2 CH(CF 3 )CH 2 CHFCH 2 —.

8. The lithium-ion battery according to claim 7 , wherein the high oxidation potential solvent is selected from one or more of the following compounds:

9. The lithium-ion battery according to claim 1 , wherein

based on a total weight of the nonaqueous solvent, a weight percentage of the two compounds respectively represented by formula I and formula II is 10% to 60%; and

based on the total weight of the nonaqueous solvent, a weight percentage of the carbonate solvent is 40% to 90%.

10. The lithium-ion battery according to claim 1 , wherein

based on a total weight of the nonaqueous solvent, a weight percentage of the two compounds respectively represented by formula I and formula II is 20% to 40%; and

based on the total weight of the nonaqueous solvent, a weight percentage of the carbonate solvent is 60% to 80%.

11. The lithium-ion battery according to claim 1 , wherein

the lithium salt is selected from one or more of LiPF 6 , LiN(CF 3 SO 2 ) 2 , LiN(FSO 2 ) 2 , LiBF 4 , LiCF 3 SO 3 , and LiClO 4 .

12. The lithium-ion battery according to claim 1 , wherein

the lithium salt is a mixed lithium salt formed by LiPF 6 and LiN(FSO 2 ) 2 .

13. The lithium-ion battery according to claim 1 , wherein

the nonaqueous electrolyte further comprises a film-forming additive; and

the film-forming additive is selected from one or more of a cyclic carbonate compound with an unsaturated bond, a halogen-substituted cyclic carbonate compound, a sulfate compound, a sulfite compound, a sultone compound, a disulfonate compound, a nitrile compound, an aromatic compound, an isocyanate compound, a phosphazene compound, a cyclic anhydride compound, a phosphite compound, a phosphate compound, a borate compound, and a carboxylate compound.

14. The lithium-ion battery according to claim 13 , wherein

the film-forming additive comprises at least the ethylene sulfate.

15. The lithium-ion battery according to claim 13 , wherein

the film-forming additive comprises at least both the ethylene sulfate and the fluoroethylene carbonate.

16. A battery pack, comprising a plurality of lithium-ion batteries, wherein each one of the lithium-ion batteries comprises a positive electrode plate, a negative electrode plate, a separator, and a nonaqueous electrolyte, wherein

the positive electrode plate comprises Li 1+x Ni a Co b Me (1−a−b) O 2−c Y c , wherein −0.1≤x≤0.2, 0.8≤a<1, 0<b<1, 0<(1−a−b)<1, 0≤c<1, Me is selected from one or more of Mn, Al, Mg, Zn, Ga, Ba, Fe, Cr, Sn, V, Sc, Ti, and Zr, and Y is selected from one or more of F, Cl, and Br;

the nonaqueous electrolyte comprises a nonaqueous solvent and a lithium salt, wherein the nonaqueous solvent comprises a carbonate solvent and a high oxidation potential solvent, and the high oxidation potential solvent comprises two compounds respectively represented by formula I and formula II;

in formula I, R 1 and R 2 are independently selected from unsubstituted, partially halogenated, or fully halogenated alkyl groups having 1 to 5 carbon atoms, and at least one of R 1 and R 2 is a partially halogenated or fully halogenated alkyl group having 1 to 5 carbon atoms; and

in formula II, R 3 is selected from partially halogenated or fully halogenated alkylidene groups having 1 to 6 carbon atoms, wherein,

a halogen atom is selected from one or more of F, Cl, Br, and I; and

wherein the high oxidation potential solvent includes both the compound represented by formula I and the compound represented by formula II;

wherein based on a total weight of the nonaqueous solvent, a weight percentage of the two compounds respectively represented by formula I and formula II is greater than 10%.

17. An apparatus, comprising a lithium-ion battery, wherein the lithium-ion battery comprises a positive electrode plate, a negative electrode plate, a separator, and a nonaqueous electrolyte, wherein

the positive electrode plate comprises Li 1+x Ni a Co b Me (1−a−b) O 2−c Y c , wherein −0.1≤x≤0.2, 0.8≤a<1, 0<b<1, 0<(1−a−b)<1, 0≤c<1, Me is selected from one or more of Mn, Al, Mg, Zn, Ga, Ba, Fe, Cr, Sn, V, Sc, Ti, and Zr, and Y is selected from one or more of F, Cl, and Br;

the nonaqueous electrolyte comprises a nonaqueous solvent and a lithium salt, wherein the nonaqueous solvent comprises a carbonate solvent and a high oxidation potential solvent, and the high oxidation potential solvent comprises two compounds respectively represented by formula I and formula II;

in formula I, R 1 and R 2 are independently selected from unsubstituted, partially halogenated, or fully halogenated alkyl groups having 1 to 5 carbon atoms, and at least one of R 1 and R 2 is a partially halogenated or fully halogenated alkyl group having 1 to 5 carbon atoms; and

in formula II, R 3 is selected from partially halogenated or fully halogenated alkylidene groups having 1 to 6 carbon atoms, wherein,

a halogen atom is selected from one or more of F, Cl, Br, and I; and

wherein the high oxidation potential solvent includes both the compound represented by formula I and the compound represented by formula II;

wherein based on a total weight of the nonaqueous solvent, a weight percentage of the two compounds respectively represented by formula I and formula II is greater than 10%;

wherein the lithium-ion battery is used as a power supply for the apparatus.

18. The apparatus according to claim 17 , wherein the apparatus is one selected from the group consisting of a full electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, an electric bicycle, an electric scooter, an electric golf cart, an electric truck, an electric vessel, and an energy storage system.