Investigating the Exfoliated Hexagonal Boron Nitride Nanosheets Embedded on Bi2S3 Nanorods Designed as a Positive Electrode for Hybrid Supercapacitors

The innovative use of a 2D composite material with a specific morphology plays a predominant role in futuristic supercapacitor applications. This study involves a nanocomposite of exfoliated h-BN nanosheets-Bi2S3 nanorods, prepared using an ultrasonic approach that offers a stacked layer, a high surface-to-volume ratio, and good electrical conductivity, leading to a high integral area in cyclic voltammetry (CV) analysis and longer charging and discharging time in galvanostatic charge–discharge (GCD) studies, demonstrating higher specific capacities and the ability to store charge for a longer time period. The morphology of exfoliated h-BN-Bi2S3 NCs was studied using HRTEM analysis, revealing that the exfoliated h-BN nanosheets that consist of nanoplatelets are well-embellished on the Bi2S3 nanorods. Moreover, the electrochemical activities of the exfoliated h-BN-Bi2S3 NCs were evaluated in a three-electrode system, which exhibits an outstanding specific capacity of 779.9 C/g at a scan rate of 10 mV/s and excellent capacitive retention of 94.3% over 5000 cycles. In addition, for real-life applications, a hybrid supercapacitor (HSC) device of exfoliated h-BN-Bi2S3//AC was designed, and its electrochemical properties were examined in a two-electrode system, which delivers an excellent energy density (EHD) of 69.8 Wh/kg, corresponding to a power density (PHD) of 1689.7 W/kg, and shows 92.5% retention over 6000 cycles.