Process for preparing by crushing, a homogenous mixture of particles containing a conductive nucleus including at least one graphite and continuously or discontinuously coated with at least one material that is different from the one constituting the nucleus, the size of the particles of the nucleus being larger than the particles used for coating the nuclei by crushing the particles together. The mixtures of particles obtained show electrochemical and mechanical properties that enable them to be advantageously used in electrochemical batteries and in paints.