The invention refers to a two-step synthesis method for the preparation of equally distributed particles of insertion active compounds for lithium-ion batteries. In the first step a modified sol-gel method is used to prepare nanoparticles of a precursor without lithium in a porous matrix of a carbon film. The first step of the synthesis method comprises sol preparation, gelling, drying and thermal treatment in a selected atmosphere. The precursor obtained in the first step is then ground with a compound, which is a source of lithium, in stoichiometric ratio and after a solid-state reaction thermally treated in a selected temperature interval. The product so obtained is crystallographically pure, equally sized particles of insertion active compounds (LiMP04, Li2MSi04, LiMB03 and mixed oxides of transition metals having a general formula LiyMX04, wherein M = Mn, Fe, Co and Ni, X=Ti and Al and y=1-3), which particles, after having been subjected to synthesis, are equally distributed in a porous carbon matrix, which ensures adequate conditions for their use in lithium-ion batteries. The synthesis conditions in the first step (used precursors, precursor concentration, type of gelling and time of gel ageing, temperature and time of thermal treatment, quantity of used organic phase, thermal treatment atmosphere) have influence on the size of insertion compounds, on their distribution and on the quantity of the carbon phase.
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