The invention relates to composite core-shell particles wherein the core is a porous, carbon-based matrix which contains silicon particles enclosed in pores of the matrix; the pores containing the silicon particles have a diameter of ≥60 nm as determined by scanning electron microscopy (SEM); the shell can be obtained by carbonizing one or more carbon precursors selected from among the group comprising tars, pitches, hard carbon, soft carbon and hydrocarbons having 1 to 20 carbon atoms, resulting in a non-porous shell.