Lithium-ion batteries and related battery modules, battery packs and devices

1. A lithium-ion battery, comprising a positive electrode plate, a negative electrode plate, an electrolyte and a separator, wherein:

the positive electrode plate comprises aluminum foil as a positive electrode current collector, and a content of element copper atom as an impurity per unit area of the aluminum foil is from 0.009 g/m 2 to 0.021 g/m 2 ,

the electrolyte comprises a first lithium salt and an additive A, and the first lithium salt is a fluorine-containing sulfonimide lithium salt, and relative to total molar amount of lithium salt in the electrolyte, the fluorine-containing sulfonimide lithium salt has a molar amount of 30 mol % or higher; and

the additive A is at least one of a phosphate compound containing an unsaturated bond, a cyclic compound containing a —SO 2 — bond and a silicon-oxygen compound containing an unsaturated bond.

2. The lithium-ion battery according to claim 1 , wherein: the additive A has a reduction potential in the electrolyte ranging from 1.2 V to 0.6 V.

3. The lithium-ion battery according to claim 1 , wherein: the electrolyte has an infiltration coefficient on the surface of the positive electrode plate ranging from 0.9 μg/s to 3.0 μg/s.

4. The lithium-ion battery according to claim 1 , wherein: the electrolyte has a viscosity at 25±3° C. of less than or equal to 5 mPa·s.

5. The lithium-ion battery according to claim 1 , wherein: the fluorine-containing sulfonimide lithium salt is a lithium salt having Formula 1,

wherein R 1 and R 2 are each independently a fluorine atom, a hydrocarbon group having 1 to 8 carbon atoms or a hydrocarbon group having 1 to 8 carbon atoms substituted by fluorine, and at least one of R 1 and R 2 contains fluorine.

6. The lithium-ion battery according to claim 1 , wherein: the phosphate compound containing an unsaturated bond comprises at least one of compounds of Formula 2,

wherein R 3 , R 4 and R 5 are each independently one selected from alkenyl, alkynyl, haloalkyl, haloalkenyl, haloalkynyl and alkyl groups having 1 to 6 carbon atoms, and aryl and haloaryl groups having 6 to 10 carbon atoms; and at least one of R 3 , R 4 and R 5 contains an unsaturated bond.

7. The lithium-ion battery according to claim 1 , wherein: the cyclic compound containing a —SO 2 — bond is at least one of compounds of Formula 3 to Formula 5,

wherein R 6 is one selected from alkylene, alkenylene, alkynylene, halogenated alkylene, halogenated alkenylene, and halogenated alkynylene having 2 to 4 carbon atoms; and arylene and halogenated arylene having 6 to 10 carbon atoms;

R 7 , R 8 , R 9 and R 10 are each independently one selected from H, alkyl, alkenyl, alkynyl, haloalkyl, haloalkenyl, and haloalkynyl having 1 to 6 carbon atoms, and aryl and halogenated aryl having 6 to 10 carbon atoms; and n is 1, 2 or 3.

8. The lithium-ion battery according to claim 1 , wherein: the silicon-oxygen compound containing an unsaturated branch chain is a compound of Formula 6,

wherein R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18 are each independently selected from hydrocarbon groups having 1 to 4 carbon atoms that are unsubstituted or substituted by a halogen element; and at least one of R 11 , R 12 , R 13 , R 14 , R 15 , R 16 , R 17 , and R 18 contains an unsaturated bond.

9. The lithium-ion battery according to claim 1 , wherein: relative to total weight of the electrolyte, mass percentage of the additive A is from 0.01 wt % to 5 wt %.

10. The lithium-ion battery according to claim 1 , wherein: the electrolyte further comprises a second lithium salt, and the second lithium salt is one or more selected from LiPF 6 , LiBF 4 , LiSbF 6 , LiAsF 6 , LiClO 4 , LiN(C 2 F 5 SO 2 ) 2 , LiN(CF 3 SO 2 ) 2 , CF 3 SO 3 Li, LiC(CF 3 SO 2 ) 3 and LiB(C 2 O 4 ) 2 , and

optionally, molar ratio of the first lithium salt to the second lithium salt is in the range of from 1:1 to 20:1.

11. The lithium-ion battery according to claim 1 , wherein: the positive electrode plate contains a positive electrode active material comprising at least one of compounds represented by Formula 7 to Formula 9:

L 1+x Ni a Co b M 1−ab O 2−y A y   Formula 7

Li 1+x′ Ni a′ M′ 2−a′ O 4−y′ A y′   Formula 8

c [Li 2 MnO 3 ]·(1 −c )[LiM″ 2 O 2−y″ A y″ ]  Formula 9

wherein each A is independently one or more of S, N, F, Cl, Br and I;

in Formula 7, −0.1≤x≤0.2, 0.5≤a<1, 0.02<b<0.3, 0.55≤a+b<1, 0≤y<0.2, M includes one or more of Mn, Fe, Cr, Ti, Zn, V, Al, Zr and Ce;

in Formula in Formula 8, −0.1≤x′≤0.2, 0.4≤a′<0.6, 0<y′<0.2, M′ comprises one or more of Mn, Fe, Cr, Ti, Zn, V, Al, Zr, Mg, and Ce; and

in Formula 9, 0<c<1, 0≤y″<0.2, M″ is one or more of Ni, Co and Mn, Fe, Cr, Ti, Zn, V, Al, Zr and Ce.

12. A battery module comprising the lithium-ion battery according to claim 1 .

13. A battery pack comprising the battery module according to claim 12 .

14. A device comprising the lithium-ion battery according to claim 1 .

15. The lithium-ion battery according to claim 5 , wherein: R 1 and R 2 are each independently a fluorine atom, —CH 3 , —CF 3 , —C 2 F 5 , —C 3 F 7 , —C 4 F 9 or —CF 2 CF 2 OCF 2 CF 3 .

16. The lithium-ion battery according to claim 6 , wherein: R 3 , R 4 and R 5 have at least one branch chain having an end of a carbon-carbon unsaturated bond.

17. The lithium-ion battery according to claim 16 , wherein: all of branch chains in R 3 , R 4 and R 5 have an end of a carbon-carbon unsaturated bond.