A survey of hybrid energy devices based on supercapacitors

Developing multifunctional energy storage systems with high specific energy, high specific power and long cycling life has been the one of the most important research directions. Compared to batteries and traditional capacitors, supercapacitors possess more balanced performance with both high specific power and long cycle-life. Nevertheless, regular supercapacitors can only achieve energy storage without harvesting energy and the energy density is still not very high compared to batteries. Therefore, combining high specific energy and high specific power, long cycle-life and even fast self-charging into one cell has been a promising direction for future energy storage devices. The multifunctional hybrid supercapacitors like asymmetric supercapacitors, batteries/supercapacitors hybrid devices and self-charging hybrid supercapacitors have been widely studied recently. Carbon based electrodes are common materials used in all kinds of energy storage devices due to their fabulous electrical and mechanical properties. In this survey, the research progress of all kinds of hybrid supercapacitors using multiple effects and their working mechanisms are briefly reviewed. And their advantages and disadvantages are discussed. The hybrid supercapacitors have great application potential for portable electronics, wearable devices and implantable devices in the future.