LITHIUM-ION BATTERY AND APPARATUS
A lithium-ion battery and an apparatus are provided. The lithium-ion battery includes a battery housing, an electrolyte, and an electrode assembly. The lithium salt includes one or more of compounds represented by formula I, where n is an integer of 1 to 3, Rf 1 and Rf 2 are C m F 2m+1 , m is an integer of 0 to 5, Rf 1 and Rf 2 are the same or different, and a group margin of battery cell of the lithium-ion battery ranges from 85% to 95%. The lithium-ion battery has advantages of good cycling performance, good rate performance, high safety performance, and good low-temperature discharge performance.
1 . A lithium-ion battery, comprising:
a battery housing;
an electrolyte, comprising a lithium salt and an organic solvent; and
an electrode assembly, comprising a positive electrode plate, a negative electrode plate, and a separator; wherein
the positive electrode plate comprises a positive electrode current collector and a positive electrode membrane that is disposed on at least one surface of the positive electrode current collector and that comprises a positive electrode active material, and the negative electrode plate comprises a negative electrode current collector and a negative electrode membrane that is disposed on at least one surface of the negative electrode current collector and that comprises a negative electrode active material;
wherein
the lithium salt comprises one or more of compounds represented by formula I;
wherein n is an integer of 1 to 3;
Rf 1 and Rf 2 are C m F 2m+1 , wherein m is an integer of 0 to 5, and Rf 1 and Rf 2 are the same or different;
mass of the compound represented by formula I is 5% to 25% of total mass of the electrolyte; and
a group margin of battery cell of the lithium-ion battery ranges from 85% to 95%.
2 . The lithium-ion battery according to claim 1 , wherein the compound represented by formula I is selected from one or more of FSO 2 N − (Li + )SO 2 F, FSO 2 N − (Li + )SO 2 CF 3 , CF 3 SO 2 N − (Li + )SO 2 CF 3 , FSO 2 N − (Li + )SO 2 N − (Li + )SO 2 F, FSO 2 N − (Li + )SO 2 N − (Li + )SO 2 N − (Li + )SO 2 F, FSO 2 N − (Li + )SO 2 N − (Li + )SO 2 CF 3 , CF 3 SO 2 N − (Li + )SO 2 N − (Li + )SO 2 CF 3 , FSO 2 N − (Li + )SO 2 N − (Li + )SO 2 N − (Li)SO 2 CF 3 , and CF 3 SO 2 N − (Li + )SO 2 N − (Li + )SO 2 N − (Li + )SO 2 CF 3 .
3 . The lithium-ion battery according to claim 1 , wherein thickness of the positive electrode current collector ranges from 5 μm to 20 μm.
4 . The lithium-ion battery according to claim 1 , wherein elongation at break of the positive electrode current collector ranges from 0.8% to 4%.
5 . The lithium-ion battery according to claim 1 , wherein the positive electrode current collector is selected from aluminum foil.
6 . The lithium-ion battery according to claim 5 , wherein an aluminum oxide layer is disposed on both of two surfaces of the aluminum foil.
7 . The lithium-ion battery according to claim 6 , wherein thickness of the aluminum oxide layer ranges from 5 nm to 40 nm.
8 . The lithium-ion battery according to claim 1 , wherein single-sided coating weight of the positive electrode plate ranges from 0.015 g/cm 2 to 0.023 g/cm 2 .
9 . The lithium-ion battery according to claim 1 , wherein compacted density of the positive electrode plate ranges from 2.0 g/cm 3 to 3.5 g/cm 3 .
10 . The lithium-ion battery according to claim 1 , wherein mass of lithium hexafluorophosphate in the electrolyte is 0% to 10% of total mass of the electrolyte.
11 . The lithium-ion battery according to claim 1 , wherein the organic solvent comprises a cyclic carbonate, and mass of the cyclic carbonate is less than or equal to 10% of the total mass of the electrolyte.
12 . An apparatus, wherein a driving source or storage source of the apparatus is the lithium-ion battery according to claim 1 .