LITHIUM-RICH IRON-BASED COMPOSITE MATERIAL, PREPARATION METHOD THEREFOR AND USE THEREOF

The present application discloses a lithium-rich iron-based composite material and a preparation method and application thereof. The lithium-rich iron-based composite material includes a lithium-rich iron-based material having a molecular formular of aLiFeO2·bLi2O·cMxOy, where a, b, and c are numbers of moles, and 0 ≤ c/(a + b + c) ≤ 0.02, 1.8 ≤ b/a ≤ 2.1, M is a doping element, and 1≤ y/x ≤ 2.5. The lithium-rich iron-based composite material can provide abundant lithium, and the lithium-rich iron-based material has a high purity and low residual alkali on the surface, which lead to high capacity and good lithium supplementing effect, as well as good stability for storage and processing. The preparation method can ensure that the prepared lithium-rich iron-based composite material has a stable structure and electrochemical performance, thereby saving production costs. The application of the lithium-rich iron-based composite material in a lithium-supplementing additive for cathodes, a cathode material, a cathode and a lithium-ion battery.