This application describes an electrode material comprising particles of an electrochemically active material dispersed in a polymer binder, where the polymer binder is an acidic polymer or a mixture comprising a binder soluble in an aqueous solvent or a non-aqueous solvent (e.g. NMP) and an acidic polymer. The application also further relates to processes for the preparation of the electrode material and electrodes containing the material, as well as to the electrochemical cells and their use.