Notwithstanding the growth of the new Lithium-ion batteries market, lead-acid batteries still offer advantages that the new ones are not able to equate especially in terms of cost, manufacturing base, and the actual market need. In this context, our work aims to enhance the properties of lead-acid batteries PE- separators that predominate 90% of the lead-acid batteries separators market[1]. These porous membranes consist mainly of precipitated silica, a backbone of ultra-high molecular weight polyethylene (UHMWPE) and they are processed using a thermally induced phase separation process (TIPS) with naphthenic oil that is subsequently extracted. The resulting porosity is thereafter infiltrated with the battery electrolyte. Yet, due to the limited wettability of the membrane pores by the polar electrolyte, only a fraction of the available porosity is effectively filled. Our work focuses on the enhancement of such wettable porosity by the electrolyte to reduce the electrical resistivity of the separator. The pores wettability is not only related to the presence of silica but also the type of silica surface. Paradoxically, hydrophobic silica favors the blend miscibility, the oil retention and thus the recovery of the lost crystallinity of the melt UHMWPE[2]; while hydrophilic silica promotes the wettability of the porosity by the electrolyte. To fulfill these criteria and obtain a material as homogeneous as possible with maximum accessible porosity, surfactants were introduced onto the silica surface. According to suspension rheology, preliminary results using the Krieger- Dougherty model for rigid spheres suspensions, the surfactant impregnation at silica surface has made the silica aggregates more dispersible and fragile. Contact angle and other techniques were used to evaluate the change in the surface and form factor of particles on the one hand, and membrane resistivity, porosity, structure and mechanical properties of the membrane were investigated on the other hand. [1] W. Böhnstedt, J. Polymer Sources 133 (2004) 59-66. [2] F. Toquet, L. Guy, B. Schlegel, P. Cassagnau, R. Fulchiron, Polymer 97 (2016) 63-68.