Construction of porous carbon nanosheets by dual-template strategy for zinc ion hybrid capacitor

Abstract

Carbonaceous zinc ion hybrid capacitors (CZHCs) have attracted numerous interests thank to the advantages of large energy density of zinc-ion battery and excellent security and high power density of supercapacitors. Nevertheless, the preparation of carbon cathode is relatively complex, and it is urgent to develop a simple and efficient preparation method. Herein, the porous carbon nanosheets (C-Xs) were prepared by dual-template strategy combined K2CO3 activation from anthracene molecules, which present unique layered sheet-like structures and high surface area, displaying excellent zinc storage properties as cathode for Zn‖C-X ZHCs. Zn‖C-800 ZHC achieves high discharge capacity of 121.7 mAh g−1, maximum energy density and power density of 109.3 Wh kg−1 and 15.6 kW kg−1 in 3 M ZnSO4 electrolyte, respectively. Moreover, the capacity retention of 96.2% and coulombic efficiency of ∼100% is obtained after 30,000 cycles. This work opens up a simple and efficient rout for the synthesis of carbon nanosheet cathode by dual-template strategy for ZHC.