▎ 摘　　要

NOVELTY - A tin-carbon negative electrode material comprises metal foil, conductive adhesive layer and tin-carbon core ring composite active hole. The surface of the tin-carbon core ring composite active hole is embedded with more than one tin elemental structure, and every two adjacent tin elemental structures are arranged equidistantly. USE - Tin-carbon negative electrode material used in sodium ion battery. ADVANTAGE - The tin-carbon negative electrode material is low in preparation cost. The tin-carbon core ring structure is formed in the tin carbon, and the tin-carbon structure in the hole has extremely strong adsorbability in sodium ions. The tin simple substance is filled in inner surface of the hole of core ring, and sodium and tin can form alloy phase. A metastable state film is formed after baking, and the metastable state film can reach stable state after battery is charged and discharged and activated, so that irreversible capacity loss is reduced. The effect of the battery is improved. The tin-carbon core ring structure provides electrolyte infiltration channel, and the volume effect of tin-carbon material can be buffered, so that the cycle service life of the sodium ion battery can be greatly prolonged. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of tin-carbon negative electrode material, which involves mixing precursor fine powder raw material obtained by crushing a biomass material, and tin powder and organic solution of catalyst, mixing and stirring to obtain pretreated fine powder raw material, placing the material into high-temperature carbonization furnace, heating at constant heating rate, sintering at high temperature in inert atmosphere, introducing carbon source gas, carbonizing at high temperature, cooling to room temperature.