The configuration of BiFe-PBA derived Bi2O3/BiFeO3 rectangular nanorods and NiCo-LDH/rGO for high-performance asymmetric hybrid supercapacitor with high energy density

Abstract

The rectangular nanorods microstructure with abundant pores can reduce structural damage caused by the volume contraction during charging-discharging processes and enhance the specific capacitance. In this work, to enhance the energy density and accelerate the marketable applications of supercapacitors, Bi2O3/BiFeO3 rectangular nanorods with rich mesoporous structure derived from the iron‑bismuth based Prussian blue analogue are rationally designed to achieve a large specific capacitance through precipitation and annealing measures. There are a huge specific capacity of 741 F g−1 and long cycle life. The NiCo-LDH/rGO (954 F g−1) demonstrated an impressive stability of 86 % after 10,000 cycles and is utilized to establish asymmetric supercapacitor device. Amazingly, the NiCo-LDH/rGO//Bi2O3/BiFeO3 device achieves an enormous energy density of 59.7 Wh kg−1 at 800 W kg−1. In addition, the capacity retention ratio is 79.3 % after 7000 cycles. The work has suggested that Bi2O3/BiFeO3 has great potential as a negative electrode of supercapacitors.