Electrolytic solution, secondary battery, and power consumption apparatus
The present application provides an electrolytic solution, a secondary battery, and a power consumption apparatus. The electrolytic solution may include a solvent and an additive; the solvent may include a compound of formula I, and a mass percentage of the compound of formula I in the solvent may be 35% or more; in formula I, R 1 and R 2 are each independently selected from any one of a hydrogen atom, a C1-C3 chain alkyl group, and a C2-C3 alkenyl group; and the additive may include a compound of formula II, and in formula II, R 3 , R 4 , and R 5 are each independently selected from any one of a hydrogen atom, a fluorine atom, a phenyl group, a cyano group, a C1-C6 chain alkyl group, a C3-C6 cyclic alkyl group, and a C2-C6 alkenyl group.
1 . An electrolytic solution, comprising a solvent and an additive,
wherein the solvent comprises a compound of formula I, and a mass percentage of the compound of formula I in the solvent is 35% or more,
wherein R 1 , and R 2 are each independently selected from any one of a hydrogen atom, a C1-C3 chain alkyl group, and a C2-C3 alkenyl group;
the additive comprises a compound of formula II,
wherein R 3 , R 4 , and R 5 are each independently selected from any one of a hydrogen atom, a fluorine atom, a phenyl group, a cyano group, a C1-C6 chain alkyl group, a C3-C6 cyclic alkyl group, and a C2-C6 alkenyl group,
wherein the electrolytic solution satisfies 11≤a/b≤35,
wherein a is the mass percentage of the compound of formula I in the solvent, and
b is a mass percentage of the compound of formula II in the electrolytic solution.
2 . The electrolytic solution according to claim 1 , wherein the mass percentage of the compound of formula I in the solvent is 40%-70%.
3 . The electrolytic solution according to claim 1 , wherein a mass percentage of the compound of formula II in the electrolytic solution is 9% or less.
4 . The electrolytic solution according to claim 3 , wherein the mass percentage of the compound of formula II in the electrolytic solution is 3%-5%.
5 . The electrolytic solution according to claim 1 , wherein the compound of formula I comprises at least one selected from methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl acrylate and ethyl acrylate.
6 . The electrolytic solution according to claim 1 , wherein the compound of formula II comprises at least one of biphenyl, fluorobenzene and cyclohexylbenzene.
7 . The electrolytic solution according to claim 1 , wherein the electrolytic solution comprises an electrolyte salt, and the electrolyte salt comprises a compound of formula III, and a molar percentage of the compound of formula III in the electrolyte salt is 10% or more,
wherein R 6 and R 7 are each independently an F atom or a fluoroalkyl group, R 6 and R 7 can also be linked to form a cycle.
8 . The electrolytic solution according to claim 7 , wherein the compound of formula III comprises at least one selected from lithium bisfluorosulfonimide and lithium bis(trifluoromethanesulfonyl)imide.
9 . The electrolytic solution according to claim 1 , wherein the solvent further comprises a carbonate, and a mass percentage of the carbonate in the solvent is 30% or more.
10 . The electrolytic solution according to claim 9 , wherein the mass percentage of the carbonate in the solvent is 35%-65%.
11 . The electrolytic solution according to claim 1 , wherein the solvent further comprises ethylene carbonate, and a mass percentage of the ethylene carbonate in the solvent is 30% or more.
12 . The electrolytic solution according to claim 1 , wherein the additive further comprises at least one selected from vinylene carbonate (VC), fluoroethylene carbonate (FEC), vinyl sulfate (DTD), 1,3-propane sultone (PS), lithium difluorobisoxalate phosphate (LiDFOP), lithium difluoro (oxalato) borate (LiDFOB), and lithium bis(oxalato) borate (LiBOB).
13 . A secondary battery, comprising the electrolytic solution according to claim 1 .
14 . The secondary battery according to claim 13 , wherein the secondary battery comprises a positive electrode sheet, the positive electrode sheet comprises a positive electrode film layer, the positive electrode film layer comprises a positive active material, and the positive active material comprises an olivine-structured lithium-containing phosphate.
15 . The secondary battery according to claim 14 , wherein the secondary battery makes true 1 g/1000 m 2 ≤L≤5 g/1000 m 2 ,
L=M1/[M2×B×(a+c)]*1000,
M1 is mass of the compound of formula II with a unit of g,
M2 is mass of the positive active material with a unit of g,
B is a specific surface area of the positive active material with a unit of m 2 /g,
a is a mass percentage of the compound of formula I in the solvent, and
c is a molar percentage of the compound of formula III in the electrolyte salt.
16 . The secondary battery according to claim 15 , wherein 8 m 2 /g≤B≤16 m 2 /g.
17 . The secondary battery according to claim 15 , wherein a thickness of the single-faced positive electrode film layer is 0.08 mm or more.
18 . A power consumption apparatus comprising the secondary battery according to claim 13 .
19 . The electrolytic solution according to claim 1 , wherein the mass percentage of the compound of formula I in the solvent is 60% or more.