Performance of hybrid supercapacitors in the presence of mechanical vibrations for applications of micro-mobility

Abstract

Supercapacitors (SCs) have always been regarded as a source of electrical energy storage confined to equipment requiring high power, and particularly high currents, for a few moments. Hybrid SCs characterized by increasingly higher energy densities have been gaining ground. The main advantages of such accumulators are long service life, a high number of cycles which drastically reduces the problem of recycling lithium cells and good operation even at low temperatures. One of the most underestimated aspects, but with an impact on the service life of accumulators, is the mechanical vibration behavior. In micro-mobility vehicles, the battery pack is often attached to the charter, which in turn is not sufficiently dampened for normal road surface conditions. The literature mainly analyses the variation of ESR (internal resistance) as a function of the received vibration dose. In the following work, the impact of mechanical vibrations on the various parameters of an equivalent electrical circuit is assessed using impedance spectroscopy, and how the variation of individual components can influence the performance of a micro-mobility vehicle battery. The reference vibration cycle was realized by sampling a real driving cycle on an electric scooter on various types of urban terrain and was replicated on various types of cells using a shaker.