The invention discloses a porous-filling type hard carbon material and a preparation method thereof, and relates to the field of battery negative
electrode material preparation, resin is dissolved in water,
metal salt is added, after dissolving and uniform mixing,
spray pyrolysis is carried out to obtain mixture
powder, then primary
carbonization is carried out, then the mixture
powder is washed with dilute
nitric acid and dried, and porous hard carbon is obtained; dissolving
cane sugar in water, adding the porous hard carbon
powder, uniformly mixing, carrying out
hydrothermal treatment,
drying the turbid liquid, and carrying out secondary
carbonization so as to fill pores in the outer layer of the porous hard carbon and increase
sodium storage sites; according to the porous-filling type hard carbon material and the preparation method thereof,
sucrose filled in pores of the porous hard carbon is pyrolyzed and shrunk through secondary
carbonization to leave more pore channels for
ion transmission, and the porous characteristic of the porous-filling type hard carbon material is enhanced by increasing
ion diffusion channels, so that
electrolyte permeation is promoted; the contact area of the
electrolyte and the hard carbon material is increased, the rate capability of the material is improved, and the initial coulombic efficiency is enhanced.