High performance Bi2O2CO3/rGO electrode material for asymmetric solid-state supercapacitor application

Bi2O2CO3 and reduced graphene (rGO) are considered as promising electrode materials for the applications of supercapacitor due to their high specific capacitance and high cycle property, respectively. However, the poor conductivity of Bi2O2CO3 and low specific capacitance of rGO have restricted their practical application. In this research, we have prepared a novel Bi2O2CO3/rGO composite electrode with a unique flower-like microstructure by a facile hydrothermal synthesis. The as-prepared Bi2O2CO3/rGO composite electrode exhibits a high capacitance of 667 Fg-1 at 1 Ag-1, which is attributed to the short pathways for rapid ionic diffusion provided by the flower-like microstructure and the addition of high-conductive rGO. Furthermore, the asymmetric solid supercapacitor (ASSC) was assembled by using the Bi2O2CO3/rGO and the N/S co-doped rGO electrode, which shows excellent capacitive performance with the capacitance of 68 Fg-1 at 1 Ag-1 and high energy density of 19.85 Wh kg−1 at power density of 1051 W kg−1. In addition, the device exhibits remarkable cycle stability of about 92.6% after 4000 cycles at a current density of 3 Ag-1. The results have provided an effective way for significant improving the capacitance of Bi2O2CO3 electrode and realizing its practical application in ASSC.