Supercapacitors are often used for high power/low energy applications as capacitors are able to deliver very high discharge rates, but energy storage density is lower than batteries.
Hybrid Energy Storage Systems (HESS) consist of two or more energy storage devices that offer different attributes and together can deliver a more capable overall system. This can be a supercapacitor to deliver the high peak power demands and a battery to deliver the energy.
For a look at how supercapacitor electrodes are characterised in practice, see EIS for Supercapacitor Electrodes.
Needs review: This page is currently a brief stub. It would benefit from expansion covering supercapacitor types (EDLC vs. pseudocapacitor/hybrid capacitor), typical materials, and characteristic applications/limitations versus batteries — left for a manual pass rather than auto-generated.