Metal oxides, metal sulfides, and their derivatives exhibit impressive electrochemical capabilities, offering potential for the creation of novel electrodes with superior performance in supercapacitors. In this study, we introduce a novel binary composite consisting of copper sulfide and manganese oxide (CuS/MnO2). This composite is designed with specific CuS and MnO2 ratios (80 % and 20 %, respectively) to explore their electrochemical behavior and optimize the performance of these nanostructures. According to morphological and structural analysis, it was observed that the synthesis process yielded high-purity nanoparticles and nanorods of CuS and MnO2. Notably, no byproducts were detected, indicating a successful synthesis process. Through a rapid pseudocapacitive charge storage mechanism, the electrochemical investigations reveal that all electrodes in a three-electrode setup tested in 3 M KOH electrolyte solution and the novel CuS/MnO2 electrode exhibit typical capacitive behavior in the potential of 0.0–0.5 V, with good reversibility and charge storage properties (specific capacitance: 451 F g−1, low resistance: 1.21 Ω, cyclic stability: 98.33 % at 4 A g−1 continuously 2000 cycles). Surprisingly, the CuS/MnO2 nanocomposite (NC) exposed high power density is about 1997 W kg−1 and a maximum energy density of 28.19 W h kg−1exceptionally is achieved. The significance of additional transition metal oxide-based electrodes in achieving noticeably better performance is demonstrated by these results.

Synthesis, characterization, and synergistic effects of CuS/MnO2 nanocomposite electrodes for high-performance supercapacitors