Lithium-ion battery

1 . A lithium-ion battery, comprising a positive electrode, a negative electrode and a non-aqueous electrolyte, wherein the positive electrode comprises a positive electrode material layer, the positive electrode material layer comprises a positive electrode active material, and the positive electrode active material comprises LiMO 2 , where M is selected from one or more of Ni, Co and Mn, and the positive electrode active material is coated with a compound containing metal element A, the metal element A is selected from one or more of Al, Mg, Cr, Pb, Ti, Ba, Cu, Fe, Sr, Y, Zr, Zn, Cd, Ru, V, Mo, Ta, W, Nb and Sn;

the non-aqueous electrolyte comprises a solvent, an electrolyte salt and a compound represented by Structural formula 1:

wherein E is selected from

where G* represents a bonding position;

h is 0 or 1;

R1 is selected from a hydrogen atom, an alkyl group with 1-6 carbon atoms, a group represented by Structural formula 2 or a group represented by Structural formula 3;

R2 is selected from a group represented by Structural formula 3 or a group represented by Structural formula 2;

R3 is selected from a group represented by Structural formula 4;

L is selected from a single bond or methylene, and W is selected from

where m is an integer from 1 to 4, n is an integer from 0 to 2, and p is an integer from 0 to 6;

based on the total mass of the non-aqueous electrolyte being 100%, a percentage mass content of the compound represented by Structural formula 1 is B %; a ratio of a molar content of metal element A to a molar content of transition metal M in the positive electrode material layer per unit area is C, and F=B/C, which satisfies the following relationship:

0.25≤F≤500, 0.05%≤B %≤5%, and 0.01≤C≤0.2.

2 . The lithium-ion battery of claim 1 , wherein value F satisfies the following relationship:

1 ≤F≤ 200.

3 . The lithium-ion battery of claim 1 , wherein a coating layer is provided outside the positive electrode active material, and the coating layer is selected from an oxide containing metal element A, and a weight of the coating layer is 1-10% of the total weight of the positive electrode active material.

4 . The lithium-ion battery of claim 3 , wherein the oxide containing metal element A comprises one or more of aluminium oxide, magnesium oxide, titanium oxide, tungsten oxide, tin oxide, zinc oxide, zirconium oxide, molybdenum oxide and chromium oxide.

5 . The lithium-ion battery of claim 1 , wherein the compound represented by Structural formula 1 is selected from one or more of the following compounds:

6 . The lithium-ion battery of claim 1 , wherein the positive electrode material layer further comprises a positive electrode binder, and the positive electrode binder comprises polyvinylidene fluoride.

7 . The lithium-ion battery of claim 1 , wherein the solvent comprises one or more of cyclic carbonate, linear carbonate, carboxylic ester and ether.

8 . The lithium-ion battery of claim 1 , wherein the non-aqueous electrolyte further comprises a supplemental additive, and the supplemental additive comprises one or more of unsaturated cyclic carbonate, fluorinated cyclic carbonate, cyclic sultone and cyclic sulfate.

9 . The lithium-ion battery of claim 2 , wherein value F satisfies the following relationship:

5≤ F≤ 80.

10 . The lithium-ion battery of claim 4 , wherein a lattice energy of the oxide containing metal element A is less than 4000 Kj/mol.

11 . The lithium-ion battery of claim 1 , wherein the percentage mass content of the compound represented by Structural formula 1 is 0.1-3% based on the total mass of the non-aqueous electrolyte being 100%;

a range of C is 0.01-0.1.

12 . The lithium-ion battery of claim 1 , wherein the electrolyte salt comprises one or more of LiPF6, LiBF4, LiPO2F2, LiBOB, LIDFOB, LiSbF6, LiAsF6, LiN(SO2CF3)2, LiC(SO2CF3)3 and LiN(SO2F)2; and

a content of the electrolyte salt is 0.5-3.5 mol/L in the non-aqueous electrolyte.

13 . The lithium-ion battery of claim 8 , wherein the percentage mass content of the supplemental additive is 0.1%-5% based on the total mass of the non-aqueous electrolyte being 100%.

14 . The lithium-ion battery of claim 8 , wherein the fluorinated cyclic carbonate is selected from one or more of fluoroethylene carbonate, trifluoromethyl vinylethylene carbonate and bisfluoroethylene carbonate;

the cyclic sultone is selected from one or more of 1,3-propane sultone, 1,4-butane sultone and propenyl-1,3-sultone; and

the cyclic sulfate is selected from one or more of ethylene sulfate and 4-methyl ethylene sulfate.