@thardin The main difference between batteries and supercacitors is in power and energy densities. Supercapacitors are very powerful, that is, they can deliver all their energy in a very short time, but compared to batteries the total stored energy (per kg) is very low: they have high power density but poor energy density.
Inversely, (lithium-ion) batteries can store a big amount of energy but they can not be charged/discharged very quickly.
The applications of both devices are different.