The present application relates to the technical field of
sodium ion battery negative
electrode material, and specifically to modified hard carbon negative
electrode material and its preparation method and application, the present application takes
biomass waste oil tea shell as
raw material, adopts
sulfuric acid and
phosphoric acid as
dopant, carries out porosification and activation, obtains P, S double atom
doping pre-
carbonization porous carbon material after
carbonization, takes
tetraethyl orthosilicate as
raw material to prepare nano SiO2 microspheres under
catalysis, carries out
carbonization after blending nano SiO2 microspheres and P, S double atom
doping pre-carbonization
porous carbon material, obtains modified hard carbon negative
electrode material through
pyrolysis reaction with
magnesium powder at the same time of carbonization, the element
doping in modified hard carbon negative
electrode material provides more active sites for
sodium ion storage, improves the theoretical capacity and
conductivity of the material, and the nanoscale
silicon powder reduces the pulverization phenomenon caused by
volume expansion when
silicon is used as the negative
electrode material of
sodium ion battery due to the special size effect, reduces the attenuation of
battery capacity.