Benefits of controlling plate-group expansion: opening the door to advanced lead/acid batteries

Highly compressed, flooded-electrolyte cells have been constructed with pure-lead positive plates prepared from the following starting materials: (i) standard positive paste; (ii) standard negative paste; (iii) mixture of lead sulfate and barium sulfate; (iv) active-material removed from a cured negative-plate. All the cells return excellent cycle lives under deep-cycle service. The exceptional performance is attributed to the high level of cell-group compression that minimizes active-material shedding and maintains electrical conductivity within the positive active-mass. The results demand that traditional methods used to process battery plates be reviewed, especially in terms of positive-paste composition and curing conditions. Cost-effective strategies are identified to assist in the implementation of significant cell-group compression into commercial gelled- and flooded-electrolyte batteries. This involves the development of devices that apply accurate support to the cell group along with a compression-resistant separator system that can withstand high levels of compression. (C) 1997 Published by Elsevier Science S.A.