ABSTRACT
One of the most convenient ways to briey introduce supercapacitors is certainly to compare their performances toward those of batteries. The obvious discrepancies between these two electrochemical storage devices are rstly evidenced in the Ragone plot depicted in Figure 5.1. Supercapacitor energy densities roughly lie in the range from 0.05 to 10 W h/kg, while their power density is from 1 to 105 W/kg.1 Time constants, which are related to charge/discharge rate, are typically from 0.01 s to 30 min. In terms of energy and power densities and time constants, supercapacitors tend to ll the gap in between conventional electrolytic capacitors and batteries. They do not aim at replacing any of these two types of devices. They should be considered as dedicated power sources for specic uses including electronic tools, automotive start/stop systems, and brake energy harvesting or as a part of an advanced storage system, eventually including other storage and/or conversion devices for renewable energy harvesting and grid regulation, for example.
