The invention discloses a preparation method of a
silicon /
porous carbon nano-composite particle, comprising the following steps: dispersing silica beads, hexachlorocyclotriphosphazene and 4,4'-dihydroxydiphenylsulfone into an
organic solvent under an
ultrasound condition, then adding
triethylamine, an acid binding agent, into the
solvent for ultrasonic reaction at a temperature of 20-40 DEG C for 6-10h, and after the reaction, obtaining a core-shell structured
silicon /
polyphosphazene nano-composite particle through the processes of
centrifugal separation, washing and
vacuum drying; transferring the obtained
silicon /
polyphosphazene nano-composite particle into a
quartz tube type carbonizing
plant, under the protection of
inert atmosphere, heating up the
plant at a rate of 1-5 DEG C / min and insulating the
plant at a temperature of 600 DEG C for 2h, then continuing heating up the plant at a rate of 1-5 DEG C / min to a preset temperature of 700-1000 DEG C and insulating the plant for 5h, then naturally cooling the plant to
room temperature, thus obtaining the silicon /
porous carbon nano-composite particle. The silicon /
porous carbon nano-composite particle has the core-shell structure with the silica beads as the core and the porous carbon as the shell. The specific capacity of
lithium-
ion batteries using the silicon / porous carbon nano-composite particle as the
anode material is higher than 950mAh / g, the initial efficiency thereof reaches 73% and the capacity decrease after 40 cycles is as low as 7.5-38%, therefore, the
lithium-
ion batteries show higher specific capacity, higher initial efficiency and good cycle stability.