Synthesis of high-performance CdS/MnO composite electrode to achieve high energy and power densities for asymmetrical supercapacitors

High-performance CdS-MnO composite electrode has been prepared to achieve high energy and power densities for asymmetrical supercapacitors. • A simple chemical method is employed to prepare a CdS-MnO composite with high electric conductivity and electrochemical stability. • CdS and MnO are homogeneously mixed, leading to a fast kinetic for charge transfer during charge–discharge process. • The asymmetrical supercapacitors assembled from this CdS-MnO composite can deliver high energy and power densities of 36.88 Wh kg −1 and 799.8 W kg −1 , respectively. Developing electrode materials with exceptional durability, energy density, and rate performance is very interesting for next-generation supercapacitor applications. This work used a simple wet chemical method to synthesize a cost-effective composite electrode based on CdS and MnO to achieve high energy and power densities of asymmetric supercapacitors (ASCs). The composite shows excellent conductivity, a large specific surface area, and high cycling stability. It exhibits remarkable rate capability by achieving a specific capacitance of 1020 F/g at 1 A g −1 and maintaining 90.3% capacitance after 5000 cycles at 10 A/g. Integrated into a CdS-MnO||AC ASC, the device exhibits outstanding overall energy and power capabilities by delivering a high energy density and maintaining a stable performance at high power densities. The components’ synergistic interaction significantly improves the supercapacitor’s performance, providing a capable method for enhancing energy storage systems.