The investigations were initially carried out on commercially available lead sulphuric acid batteries, as these are currently still very frequently used as decentralised energy storage systems. In addition, they have a comparatively simple structure and the chemical processes taking place in them have been sufficiently understood. Lead batteries consist of negative lead and positive lead oxide plates which are separated from each other by separators. 37% sulphuric acid acts as electrolyte. The electrodes consist of a grid. In order to systematically investigate the influence of interfacial waves on the charging time of lead-acid batteries, a semi-automated test stand was set up to carry out defined charging and discharging cycles with and without acoustic coupling. The results obtained with this test stand show that surface waves can also be excited on the lead electrodes – despite the grid-shaped electrodes, the surface waves propagate over the entire electrode, which can be measured using a laser doubler vibrometer.
If one compares the charge curves of a lead acid battery without excitation of boundary surface waves on the electrodes with experiments in which boundary surface waves are excited, a visible influence on the charge curve can be determined. So far, charging times can be reduced by up to 10%. It is conceivable that the charging time could be reduced by around 25% by further optimization steps. ISAT is also currently working on the construction and commissioning of a redox flow cell and would like to transfer the knowledge gained to date to this innovative energy storage device of the future