▎ 摘　　要

NOVELTY - Modified positive electrode lithium supplement additive comprises a metal element-doped lithium-rich lithium ferrite nucleus and a carbon-sulfur composite coating coated on the outer surface of the metal element-doped lithium-rich lithium ferrite nucleus cladding, where the thickness of the carbon-sulfur composite coating layer is 1-20 nm, and the sulfur and carbon are evenly distributed in the carbon-sulfur composite coating layer, and the sulfur content is 0.01-0.5 wt.%, and the carbon content is 0.1-5 wt.%. USE - The modified positive electrode lithium supplement additive is used for preparing lithium ion batteries (claimed). ADVANTAGE - The modified cathode lithium supplement additive has a simple preparation method, low-temperature preparation, low energy consumption and wide applicability, can be applied to the preparation of the cathode of a lithium-ion battery, and improves the first efficiency and overall electrochemical performance of the battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: a method for preparing the modified positive electrode lithium supplement additive comprising (a) mixing the mixed solution of lithium source, iron source, doping metal source and water evenly by ball milling to obtain a slurry, (b) spray drying the slurry to obtain a precursor powder, (c) calcining the precursor powder in an inert gas atmosphere for a certain period of time, and cooling with the furnace to obtain doped lithium-rich lithium ferrite, and (d) adding an organic solvent to the doped lithium-rich lithium ferrite, sulfur, and amorphous carbon, carrying out vacuum ball milling, using a closed spray dryer to dry the powder and recover the solvent, and keep the temperature under vacuum for a certain period of time, and obtaining the modified cathode lithium supplement additive; and an application of the modified positive electrode lithium supplement additive is used to prepare lithium ion batteries.