▎ 摘　　要

NOVELTY - A cathode material has a graphene/carbon/tin dioxide core-shell cavity nanocomposite structure made of core layer including tin dioxide porous nanospheres and outer shell including graphene nanosheet. The core layer and outer shell are connected by multi-contact of carbon nanotube. USE - Cathode material is useful for sodium-ion battery. ADVANTAGE - The cathode material has high specific capacity and excellent rate performance, cycle stability and structural characteristics. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of cathode material, which involves weighing tin dioxide porous nanospheres and then hydrothermally processing, coating using layer of silicon dioxide and layer of polydopamine, adding polyvinyl alcohol and graphene oxide aqueous solution and then continuously stirring at 50-70 degrees C for 8-12 hours, molding the mixture and then freezing, placing the mixture in sodium hydroxide aqueous solution at 50-70 degrees C for 8-12 hours and processing.