The role of additives in the positive active mass of the lead/acid cell

Abstract Leadacid cells have been assembled with tubular positive plates containing chemically prepared PbO 2 admixed with a small mass fraction of second phase material. The manner in which graphite, in particular, affects the initial discharge capacity of cells prepared in this way has been examined. It has been shown that in addition to its influence on porosity and diffusive mass transport in the cell, the possibility that an additive gives rise to electro-osmotic pumping must be considered where the material added has a high zeta potential. Electro-osmotic pumping offers a means to improve the performance of leadacid battery plate regardless of the method used to prepare them.