Abstract: A cell includes a separator comprising a felt type macroporous matrix the pores of which contain a PVDF type microporous polymer. The microporous polymer is placed in the macroporous matrix by impregnating the matrix with a solution containing the polymer. A method of preparing the cell includes the following steps: a bonding solution is produced containing a polymer, a solvent and a non-solvent; the macroporous matrix is impregnated with the solution; the impregnated macroporous matrix and the two electrodes are brought into contact to form an electrode assembly; and the assembly is dried to eliminate the solvent and the non-solvent.