Method of preparing hard carbon anode material and use thereof

Abstract

The present invention discloses a method of preparing a hard carbon anode material and use thereof. Starch is mixed with nano-silica, the obtained mixture is heat treated at 150° C. to 240° C. under an inert atmosphere, the obtained first-sintered product is heat treated at 180° C. to 220° C. under an oxygen-containing atmosphere, the second-sintered product is cyclonically separated to remove nano-silica to obtain pre-oxidized starch-based microspheres, and the pre-oxidized starch-based microspheres are performed carbonization treatment under an inert atmosphere to obtain the hard carbon anode material. In the present invention, the silica particles can be adsorbed on the surface of the starch raw material, and cross-linking occurs between the starch molecular chains during the heat treatment process, and under the barrier of the silicon dioxide, the starch particles will not be cross-linked but fused to form a spherical structure. The introduction of oxygen atoms during the pre-oxidation process produces oxygen vacancy and increases the active sites for sodium ion storage after carbonization, thus increasing the reversible capacity of sodium ion batteries.