▎ 摘　　要

NOVELTY - Graphene/iron diselenide composite material comprises corrugated graphene nanosheets, iron diselenide nanoparticles uniformly distributed on the corrugated graphene nanosheets, and iron diselenide nanoparticles wrapped by the corrugated graphene nanosheets. USE - Graphene/iron diselenide composite material used for lithium ion battery negative material (Claimed). ADVANTAGE - Graphene/iron diselenide composite material is used as a lithium ion battery cathode material, the volume expansion of the iron diselenide during lithium intercalation is effectively reduced, the specific capacity and the rate capability of the electrode material are obviously improved, the defect of a single iron diselenide material is well overcome, and the preparation method is short process flow, simple and controllable operation, low cost and easy mass industrial production. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation method of graphene/iron diselenide composite material involves treating graphene oxide dispersion liquid ultrasonically until uniformly dispersed, then adding iron(II) chloride tetrahydrate, and magnetically stirring until uniformly mixed to obtain a graphene oxide dispersion liquid containing ferrous ions. Adding selenium powder to hydrazine hydrate, stirring magnetically until it is completely dissolved to obtain a hydrazine hydrate solution of selenium. Under the condition of magnetic stirring, adding hydrazine hydrate solution of selenium dropwise to the graphene oxide dispersion liquid containing ferrous ions, and the magnetic stirring is continued for 0.5-4 hours to obtain a mixed dispersion liquid. Transferring the mixed dispersion to a hydrothermal reactor, hydrothermally reacted at 120-200degrees Celsius for 4-12 hours, naturally cooling to room temperature, washing by repeated centrifugation with distilled water, and freeze-drying.