LITHIUM METAL NEGATIVE ELECTRODE PLATE, ELECTROCHEMICAL APPARATUS, AND ELECTRONIC DEVICE
A lithium metal negative electrode plate, an electrochemical apparatus, and an electronic device are provided. In some embodiments, the lithium metal negative electrode plate includes copper foil and a carbon material coating layer formed on at least part of a surface of the copper foil, where thickness of the carbon material coating layer is less than or equal to 10 μm, and the carbon material coating layer includes a carbon material and a polymer binder. The lithium metal negative electrode plate, the electrochemical apparatus, and the electronic device provided in this application can effectively suppress formation and growth of lithium dendrites, thereby significantly improving first-cycle charge-discharge coulombic efficiency, cycling stability performance, and safety performance of batteries.
1 . A lithium metal negative electrode plate, comprising:
copper foil;
a carbon material coating layer formed on at least part of a surface of the copper foil, wherein a thickness of the carbon material coating layer is less than or equal to 10 μm, and the carbon material coating layer comprises a carbon material and a polymer binder; and
a lithium metal alloy formed on at least part of a surface of the carbon material coating layer.
2 . The lithium metal negative electrode plate according to claim 1 , wherein the lithium metal negative electrode plate satisfies at least one of the following conditions:
the carbon material comprises at least one of meso-carbon microbeads, graphite, natural graphite, expanded graphite, artificial graphite, glassy carbon, carbon-carbon composite material, carbon fibers, hard carbon, porous carbon, highly oriented graphite, three-dimensional graphite, carbon black, carbon nanotubes, and graphene;
a mass percentage of the carbon material in the carbon material coating layer is 90% to 99%;
the thickness of the carbon material coating layer is 0.3 μm to 10 μm; or
the thickness of the carbon material coating layer is 1 μm to 7 μm.
3 . The lithium metal negative electrode plate according to claim 1 , wherein the lithium metal negative electrode plate satisfies at least one of the following conditions:
the carbon material comprises an oxygen-containing group, wherein the oxygen-containing group is selected from at least one of carboxyl group, hydroxyl group, and ether group; or
the carbon material comprises an oxygen-containing group, wherein a mass percentage of oxygen atoms in the carbon material is >0.1%.
4 . The negative electrode plate according to claim 1 , wherein a chemical formula of the lithium metal alloy is LiR, and metal R is selected from at least one of Ag, Mo, In, Ge, Bi, and Zn.
5 . The negative electrode plate according to claim 4 , wherein the lithium metal negative electrode plate satisfies at least one of the following conditions:
a mass percentage of element R in the lithium metal alloy is 1% to 10%; or
the lithium metal alloy is a solid solution alloy.
6 . The negative electrode plate according to claim 1 , wherein the polymer binder comprises at least one of sodium cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, sodium hydroxymethyl cellulose, potassium hydroxymethyl cellulose, diacetyl cellulose, polyacrylic acid, sodium alginate, styrene-butadiene rubber, acrylic butadiene rubber, polypyrrole, polyaniline, epoxy resin, or guar gum.
7 . An electrochemical apparatus, comprising a positive electrode plate, a negative electrode plate, a separator, and an electrolyte, wherein the negative electrode plate is the negative electrode plate according to claim 1 .
8 . The electrochemical apparatus according to claim 7 , wherein the electrolyte comprises a solvent and a lithium salt, and the electrolyte satisfies at least one of the following conditions:
the lithium salt comprises at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium difluorophosphate, lithium bis(trifluoromethanesulfonyl)imide, lithium bis(fluorosulfonyl)imide, lithium bis(oxalato)borate, or lithium difluoro(oxalato)borate;
the solvent comprises ethylene glycol dimethyl ether and 1,3-dioxolane;
the solvent comprises ethylene glycol dimethyl ether and 1,3-dioxolane, wherein a volume ratio of the ethylene glycol dimethyl ether and the 1,3-dioxolane is (0.5-10):1; or
a concentration of the electrolyte is 0.5 mol/L to 7 mol/L.
9 . The electrochemical apparatus according to claim 7 , wherein the electrolyte satisfies at least one of the following conditions:
the electrolyte further comprises an additive, wherein the additive comprises at least one of trioxymethylene, lithium nitrate, dioxane, lithium fluorosulfonate, and fluoroethylene carbonate; or
the electrolyte further comprises an additive, wherein a mass percentage of the additive in the electrolyte is 0.1% to 10%.
10 . An electronic device, comprising the electrochemical apparatus according to claim 7 .