The influence of the pickling and curing processes in the manufacturing of positive tubular electrodes on the performance of lead-acid batteries

The effects of changing the dipping and curing times of tubular positive electrodes on the discharge capacity were investigated. The comparative study showed that longer dipping and curing times do not necessarily result in electrodes with better first capacity performance. Acid adsorption studies of tubular plates filled with lead oxide showed that about one-third of the acid, that would have been adsorbed after 15 h, was already adsorbed after 5 s of dipping. The optimum surface area and porosity of the cured active material was obtained after 1560 min of dipping. This is equivalent to the rest period used in the formation process where the plates are kept in the acid just before charging. Curing times should be kept around 24 h in order to reduce the free lead in the oxide. The study showed that the pore size distribution of the formed active material influenced the high current discharge ability more than the available surface area of the positive electrode. However, the surface area and pore size distribution changed dramatically during capacity cycling and the continuous capacity performance of the tubular electrode was partially influenced by the initial characteristics of the cured active material. (C) 2003 Elsevier Science B.V. All rights reserved.