The invention relates to the field of lead batteries. More particularly, it relates to a solid composition comprising between 5 and 60 wt. % of carbon nanofillers, preferably carbon nanotubes, dispersed homogeneously in a hydrosoluble polymer in the presence of at least one cationic component selected from alkali or alkaline-earth metal cations and ammonium ions. The invention also relates to the use of said composition for producing lead battery electrode formulations.