METHOD FOR PREPARING DOPED LITHIUM SULFIDE COMPOSITE COATED WITH GRAPHENE/CARBON AND HAVING CORE-SHELL STRUCTURE

摘要

A method for preparing doped lithium sulfide composite coated with graphene/carbon and having a core-shell structure, comprises: step (1), mixing commercial lithium sulfide with metal oxide powder, sealing the mixture into a ball milling tank, puting the tank into a ball mill to perform milling to obtain doped nano lithium sulfide; step (2), adding and dissolving a carbon source into ethanol under stirring so as to form an ethanol solution containing the carbon source; step (3), dispersing the obtained nano lithium sulfide in an ethanol solution, and adding dropwisely the ethanol solution containing the carbon source into the suspension to obtain a lithium sulfide coated with carbon; step (4) adding the lithium sulfide coated with carbon and graphene to tetrahydrofuran and performing a ultrasonic reaction so as to obtain the doped lithium sulfide composite coated with graphene/carbon and having a core-shell structure. Doping metal ions can change the crystal structure of lithium sulfide, and is beneficial to improve the bulk conductivity of lithium sulfide and the electrochemical performance thereof.