Electrode active material and preparation method thereof, electrode, battery, and apparatus
The present invention relates to an electrode active material, a preparation method thereof, an electrode, a battery, and an apparatus. The electrode active material includes: a core and a coating layer, where the core includes a ternary material, the coating layer coats the core, the coating layer includes a reaction product of a sulfur-containing compound and a lithium-containing compound, and the reaction product includes element Li, element S, and element O.
1. An electrode active material with a coating layer, comprising:
a core, comprising a ternary material selected from the group consisting of lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, and a combination thereof; and
a coating layer disposed on at least part of a surface of the core, wherein the coating layer comprises a reaction product formed by curing a solution disposed on the surface of the core, the solution comprises a solvent, a sulfur-containing compound, and a lithium-containing compound, the sulfur-containing compound is selected from the group consisting of sulfamide, aminomethanesulfonic acid, lithium bisfluorosulfonimide, thio-propionamide, thio-isobutyramide, propylene sulfide, methyl ethyl sulfide, and any combination thereof, and the reaction product comprises Li, S, and O,
wherein a weight content of S in the electrode active material is 500-5000 ppm.
2. The electrode active material according to claim 1 , wherein the weight content of S in the electrode active material is 1000-5000 ppm.
3. The electrode active material according to claim 1 , wherein the coating layer further comprises B, and a weight content of B in the electrode active material is 500-3000 ppm.
4. The electrode active material according to claim 1 , wherein the lithium-containing compound comprises a lithium salt selected from the group consisting of Li 2 O, LiOH and Li 2 CO 3 , LiNO 3 , LiPF 6 , lithium oxalate, lithium acetate, LiClO 4 , LiBF 4 , LiCF 3 SO 3 , LiAsF 6 , LiAlCl 4 , LiN(CF 3 SO 2 ) 2 , LiC(SO 2 CF 3 ) 3 , and any combination thereof.
5. The electrode active material according to claim 1 , wherein a chemical formula of the lithium nickel cobalt manganese oxides is Li x Ni d Co e Al f M 2 (1-d-e-f) O 2 , wherein 0.5≤x≤1.2, 0.3<a≤1, 0<b≤0.5, 0<c≤0.6, and M 1 is selected from one or more of Zr, Zn, Ti, Sr, Sb, Y, W, Al, B, P, and F; and
a chemical formula of the lithium nickel cobalt aluminum oxides is Li x Ni d Co e Al f M 2 (1-d-e-f) O 2 , wherein 0.5≤x≤1.2, 0.5<d≤1, 0<e≤0.5, 0<f≤0.5, and M 2 is selected from one or more of Zr, Mg, Ba, Ti, Sr, Sb, Y, W, and B.
6. The electrode active material according to claim 1 , wherein a particle size (D v 50 particle size) of the electrode active material is 1-25 μm.
7. The electrode active material according to claim 1 , wherein the coating layer further comprises P, and a weight content of element P in the electrode active material is 200-1500 ppm.
8. The electrode active material according to claim 1 , wherein the coating layer further comprises F, and a weight content of element F in the electrode active material is 500-3000 ppm.
9. A preparation method of an electrode active material comprising a core and a coating layer, comprising:
providing a core material and a coating layer forming material, wherein the core material comprises a ternary material selected from the group consisting of lithium nickel cobalt manganese oxides, lithium nickel cobalt aluminum oxides, or a combination thereof, and the coating layer forming material is a solution comprising a solvent, a sulfur-containing compound, and a lithium-containing compound, and the sulfur-containing compound is selected from the group consisting of sulfamide, aminomethanesulfonic acid, lithium bisfluorosulfonimide, thio-propionamide, thio-isobutyramide, propylene sulfide, and methyl ethyl sulfide;
disposing the coating layer forming material on the core material; and
curing the coating layer forming material and the core material to form the coating layer and the core, wherein the core comprises the core material, the coating layer is disposed on at lease part of a surface of the core and comprises a reaction product formed by the coating layer forming material, the reaction product comprises Li, S, and O, and a weight content of element S in the electrode active material is 500-5000 ppm.
10. The preparation method according to claim 9 , wherein the lithium-containing compound is a neutral lithium-containing compound or an acidic lithium-containing compound.
11. The preparation method according to claim 9 , wherein the coating layer forming material further comprises B,
a molar ratio of B to S in the coating layer forming material is 2-5:4-7 2.
12. The preparation method according to claim 9 , wherein the curing the core material and the coating layer forming material comprises: performing heat treatment at 80-300° C.; and
for 3-20 hours.
13. The preparation method according to claim 9 , wherein
a concentration of the sulfur-containing compound in the solution is 0.1-5 mol/L;
a concentration of the lithium-containing compound in the solution is 0.1-3 mol/L; and
the solvent is selected from the group consisting of water, ethanol, NMP, and any combination thereof.
14. An electrode, comprising the electrode active material according to claim 1 .
15. A battery, comprising the electrode active material according to claim 1 .
16. An apparatus, comprising the battery according to claim 15 , wherein the battery is used as a power supply unit or an energy storage unit of the apparatus; and
the apparatus is an electric apparatus, and the battery is configured to power the electric apparatus.