A THEORY OF THE GRID POSITIVE ACTIVE-MASS (PAM) INTERFACE AND POSSIBLE METHODS TO IMPROVE PAM UTILIZATION AND CYCLE LIFE OF LEAD-ACID-BATTERIES

Very often, the cycle life of batteries with antimony-free positive gr ids operating under deep-discharge cycling is determined by the grid/P AM interface. The properties of this interface are overviewed and the technological and design parameters influencing these properties, and hence determining the cycle life of the battery, are discussed. A new parameter gamma is proposed. This is defined as grams of PAM per 1 cm( 2) of grid-collector surface area. It has been established that the gr id/PAM interface consists of two layers, namely, a corrosion layer (CL ) and a layer of the active mass that collects the current from the re maining (capacity-bearing) part of the PAM (AMCL). The technological p arameters that influence the specific resistivity of both CL and AMCL, as well as the surface area of the layers through which current flows between the PAM and the collector are discussed. On the basis of the principles derived from the theory of the grid/PAM interface, batterie s are produced and tested.