This invention discloses an in-situ surface-coated LiF-coated water-resistant 4.7V
lithium cobalt oxide cathode material, its preparation method, and its applications. The
chemical formula of the
cathode material of this invention is Li. 1‑2x‑2y Co 1‑ z Mg x Ni y Al z O2@LiF, where 0≤x≤0.05, 0≤y≤0.05, 0≤z≤0.05, and x, y, and z cannot all be 0; LiF is Li 1‑2x‑2y Co 1‑z Mg x Ni y Al z O2 material
coating layer. This invention mixes
lithium metal salts,
cobalt compounds, and an F-containing
dopant to obtain a mixture; the mixture is sintered once at a high temperature, then cooled and ground uniformly, followed by a second
sintering and cooling to obtain the in-situ surface-coated water-resistant 4.7V
lithium cobalt oxide material. This invention constructs a complete, continuous, and uniformly distributed hydrophobic protective layer on the surface of
lithium cobalt oxide particles through in-situ
coating technology, effectively blocking the
corrosion of the material by
electrolyte and
moisture; the simultaneously formed elemental
doping enhances the
metal-
oxygen bond
binding energy, synergistically improving the bulk
structural stability and jointly ensuring the long cycle life of the
electrode material.