▎ 摘　　要

NOVELTY - Preparing tin-based oxide/nitrogen-doped graphene composite material comprises adding tin tetrafluoroborate, zinc tetrafluoroborate and ethylenediamine to the dispersion of graphene oxide and stirring uniformly to obtain mixture A; where the mass ratio of graphene oxide to zinc tetrafluoroborate is 1: (5-8), the molar ratio of tin tetrafluoroborate to zinc tetrafluoroborate is 1:1, and the ethylenediamine and graphene oxide dispersion liquid, the volume ratio of the solvent is (2-6) μl:1 ml; subjecting mixture A to a hydrothermal reaction at 170-200°C, cooling the reaction product, centrifuging, washing, and freeze-drying to obtain a precursor material; and calcining the precursor material at 600-680°C for 1-3 hours in a protective atmosphere. USE - Preparation method of tin-based oxide/nitrogen-doped graphene composite material for sodium ion battery and sodium ion capacitor. The tin-based oxide/nitrogen graphene composite material is useful as material of cathode-ion energy-storage device, and the energy storage device comprises a sodium ion battery and a sodium ion mixed capacitor (claimed). ADVANTAGE - The tin-based oxide/nitrogen-doped graphene composite material has high theoretical specific capacity, high electrochemical performance and stable characteristics. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a tin-based oxide/nitrogen-doped graphene composite material prepared by the above method. DESCRIPTION OF DRAWING(S) - The drawing shows an X-ray powder diffraction spectrum of SnO2/Zn2SnO4 @N - graphene composite material prepared in Example 2. 50Tin