The invention discloses a
lithium-rich
cathode material and a preparation method and an application thereof. The
lithium-rich
cathode material has a core-shell structure, and is composed of a core material
lithium-rich
solid solution and a shell material of one of layered ternary material and
spinel structure material with lithium
ionic conductivity; the preparation method I comprises the following steps: preparation of the core material, preparation of the core material coated with a shell material precursor, presintering treatment of a core-shell structure material and high-temperature
sintering treatment; and the method II comprises the following steps: preparation of the core-material precursor, preparation of a gradient structure precursor material, presintering treatment of the core-shell structure material, and high-temperature
sintering treatment. The preparation method disclosed by the invention has the advantages of being simple in technical process, nontoxic, harmless, simple in raw materials, few in byproducts, suitable for large-scale production and the like; the prepared lithium-rich
cathode material has a gradient structure; the functional effect is materialized by the structure; the core has high capacity characteristic; the
cycling stability of the material can be improved by the surface; and the lithium-rich
cathode material can be widely applied to a lithium-
ion battery.