Sedimentation study on modified lead dioxide particles – For screening of potentially effective additives for lead-acid batteries

The testing of new additives to increase the capacities and cycle lives of lead-acid batteries (LABs) is an essential step for developers and researchers. Preparing test electrodes with additives mixed into their active materials, preferably into the PAM (positive active material) is a common method, followed by time consuming measurements on such cells (for several days, even weeks). This study deals with a new promising method to help make decisions about additives’ applicability and reducing the time of investigation typically down to less than 12 h. This method is based on measuring the sedimentation of (modified) PAM samples in sulfuric acid solution. The additives mixed to PAM suspensions cause changes in the profile and rate of sedimentation processes in a unique and reproducible way. Significant correlation has been found between the sedimentation features and cycle lives of the positive electrodes. Through careful analysis of the results, useful information can be provided in significantly shorter time for researchers about the additives’ effectiveness on capacities and cycle lives of LABs. • Novel test method for pre-indicating useful additives for lead-acid batteries. • Connection between aggregations of lead dioxide particles and aging of electrodes. • Shortened investigation time of new materials for improving durability properties.