A method for preparing a particulate material consisting of a plurality of composite particles that comprise a plurality of silicon nanoparticles dispersed within a conductive pyrolytic carbon matrix, the method comprising the steps of: (a) milling a silicon starting material in the presence of a non-aqueous solvent to obtain a dispersion of silicon-containing nanoparticles having a D 50 particle diameter in the range of 30 to 300 nm in the solvent, wherein the D 50 particle diameter refers to the volume-based median particle diameter as determined by laser diffraction; (b) contacting the dispersion of silicon nanoparticles in the solvent with a pyrolytic carbon precursor selected from one or more compounds comprising at least one oxygen or nitrogen atom; (c) removing the solvent to provide silicon nanoparticles coated with the pyrolytic carbon precursor; (d) heating the coated silicon nanoparticles to a temperature in the range of 100 to 400 °C, optionally 200 to 400 °C for a period of time, optionally from 5 minutes to 10 hours, before step (e); and (e) pyrolysing the coated silicon nanoparticles at a pyrolysis temperature in the range of from 600 to 1200 °C to form said plurality of composite particles that comprise a plurality of silicon nanoparticles dispersed within a conductive pyrolytic carbon matrix; wherein the pyrolytic carbon precursor is selected from one or more aromatic or aliphatic carbon-containing compounds comprising at least one oxygen or nitrogen atom and comprising one or more electrophilic functional groups; wherein step (d) comprises crosslinking the silicon nanoparticles and the pyrolytic precursor by a reaction between nucleophilic functional groups on the surface of the silicon nanoparticles and the electrophilic functional groups of the pyrolytic carbon precursor; and wherein (i) step (d) comprises mixing or agitating the coated silicon nanoparticles so as to ensure a homogenous reaction temperature during the crosslinking step; and/or (ii) step (d) is carried out in the presence of oxygen gas, optionally in the presence of air; and/or (iii) step (d) further comprises maintaining the coated silicon nanoparticles at a temperature in the range of from 100 to 400 °C for a period of time after completion of the crosslinking reaction. (a) milling a silicon starting material in the presence of a non-aqueous solvent to obtain a dispersion of silicon-containing nanoparticles having a D 50 particle diameter in the range of 30 to 300 nm in the solvent, wherein the D 50 particle diameter refers to the volume-based median particle diameter as determined by laser diffraction; (b) contacting the dispersion of silicon nanoparticles in the solvent with a pyrolytic carbon precursor selected from one or more compounds comprising at least one oxygen or nitrogen atom; (c) removing the solvent to provide silicon nanoparticles coated with the pyrolytic carbon precursor; (d) heating the coated silicon nanoparticles to a temperature in the range of 100 to 400 °C, optionally 200 to 400 °C for a period of time, optionally from 5 minutes to 10 hours, before step (e); and (e) pyrolysing the coated silicon nanoparticles at a pyrolysis temperature in the range of from 600 to 1200 °C to form said plurality of composite particles that comprise a plurality of silicon nanoparticles dispersed within a conductive pyrolytic carbon matrix; wherein the pyrolytic carbon precursor is selected from one or more aromatic or aliphatic carbon-containing compounds comprising at least one oxygen or nitrogen atom and comprising one or more electrophilic functional groups; wherein step (d) comprises crosslinking the silicon nanoparticles and the pyrolytic precursor by a reaction between nucleophilic functional groups on the surface of the silicon nanoparticles and the electrophilic functional groups of the pyrolytic carbon precursor; and wherein (i) step (d) comprises mixing or agitating the coated silicon nanoparticles so as to ensure a homogenous reaction temperature during the crosslinking step; and/or (ii) step (d) is carried out in the presence of oxygen gas, optionally in the presence of air; and/or (iii) step (d) further comprises maintaining the coated silicon nanoparticles at a temperature in the range of from 100 to 400 °C for a period of time after completion of the crosslinking reaction. (i) step (d) comprises mixing or agitating the coated silicon nanoparticles so as to ensure a homogenous reaction temperature during the crosslinking step; and/or (ii) step (d) is carried out in the presence of oxygen gas, optionally in the presence of air; and/or (iii) step (d) further comprises maintaining the coated silicon nanoparticles at a temperature in the range of from 100 to 400 °C for a period of time after completion of the crosslinking reaction.