INFLUENCE OF PERFLUORINATED SURFACTANTS ON THE POSITIVE ACTIVE-MATERIAL OF LEAD ACID BATTERIES/

The influence of perfluorinated anionic (FC-99), cationic (FC-135), an d non-ionic (FSN) surfactants on the discharge capacities and cycle li ve of Plante positive electrodes in sulfuric acid are studied by cycli c voltammetry, charge/discharge cycling, X-ray diffraction, and scanni ng electron microscopy. The discharge capacities of PbO2 electrodes, i .e., the utilization of the positive active-material, are increased fo r the electrolytes with FC-99 or FC-135, but the cycle live both surfa ctants are reduced. On the other hand, the presence of FSN has negligi ble influence on the discharge capacity and the cycle life of the PbO2 electrode. The differences in the effects of the various types of per fluorinated surfactants are discussed with respect to the adsorption o f perfluorinated surfactant molecules on the PbO2 electrode surface du ring the charge and/or the discharge process. (C) 1998 Elsevier Scienc e S.A.