Ultrafast Manufacturing of Ultrafine Structure to Achieve An Energy Density of Over 120 Wh kg~(?1) in Supercapacitors

摘要

Supercapacitor (SC) is one of the most promising electrochemical energy-storagedevices. However, the practical application of SCs is limited by the low-energydensity. Herein, high-temperature shock (HTS)-derived ultrafine structure-activatedporous carbon (UAPC) with N, O functional groups is reported as highenergydensity SCs carbon. The process of ultrafast joule heating and coolingeffectively transfers general-purposed carbon into electrochemical-activatedcarbon. The UAPC-based SCs exhibit an energy density of up to 129 Wh kg~(?1) inEMIMBF4 ionic liquid, which outperform almost all reported and commercial SCs(22 Wh kg~(?1)). The outstanding electrochemical performance of UAPC is attributedto the ultrafine structure and N, O functional groups, which enlarges the surfacearea, improves the surface wettability of UAPC electrodes, and provides pseudocapacitance.The facile and efficient ultrafast-processing strategy has openedup an unprecedented pathway for the application of low-value carbon for theelectrode design and application of SCs.