▎ 摘　　要

NOVELTY - Preparation of composite three-dimensional cathode material involves immersing clean copper base material in electrolyte containing sodium sulfide, anodizing using copper base as anode at current of 5-30 mA, immersing anodized product in graphene oxide suspension to obtain black active material, and annealing at 120-200 degrees C in inert atmosphere. USE - Preparation of composite three-dimensional cathode material for manufacturing sodium ion battery (claimed). ADVANTAGE - The method provides cathode material which improves the overall energy density, electron transmission efficiency, and electrochemical performance of the battery. The manufacturing method of battery is economical and installation is simple. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (i) sodium ion battery, which comprises cathode comprising cathode material, metallic sodium as counter electrode, 1 M sodium hexafluorophosphate-ethyl carbonate solution as electrolyte, and Celgard 2400 (RTM: monolayer polypropylene membrane) as separator; and (ii) manufacture of sodium ion battery.