The invention belongs to the field of
electrochemistry and energy material, and discloses a preparation method of a
biomass derivative carbon material used for
sodium-
ion batteries. According to the preparation method, soybean is taken as a
biomass source, KOH is taken as an activator, high temperature calcining is carried out so as to obtain the porous
biomass derivative carbon material. Soybeanis a
natural product, is abundant in sources, is high in
protein content, contains a large amount of
nitrogen element, and is capable of forming a natural
nitrogen doped carbon material; the nitrogendoped carbon material can be used for providing Na<+> with sufficient
sodium embedding vacancies, providing substantial fake
capacitance in
sodium-
ion battery charging and discharging process, and increasing battery specific capacity; and in addition,
nitrogen element
doping is capable of improving material
conductivity, and increasing iron transmission efficiency; KOH activation is capable of increasing porous structure specific surface area further, it is beneficial for
electrolyte infiltration, and increasing of
ion and
electron transmission efficiency. The biomass derivative carbon material possesses the above advantages, so that when the biomass derivative carbon material is taken as a sodium ion
anode material, relatively high reversible specific capacity and excellent circulation stability are achieved.