Multi-heteroatoms-doped carbon spheres loaded with manganese dioxide as an electrode for supercapacitors

Abstract Supercapacitors (SCs) have garnered extensive attention because of their excellent safety and high energy density. Nevertheless, the performance of electrode materials essentially limits the development of SCs. Among various electrode materials, manganese dioxide (MnO 2 ) has drawn interest due to its high theoretical capacity. However, the inherent semiconductor properties of MnO 2 restrict its electron transfer capability, while the structural instability of MnO 2 during charge-discharge processes further hinders its practical applications. In this study, we utilized the synergistic enhancement effect of heteroatoms doped carbon materials on MnO 2 , synthesizing N, S, and P co-doped carbon spheres loaded with MnO 2 (MnO 2 @NSPC). As a result, MnO 2 @NSPC exhibits outstanding specific capacitance and cycling performance. When tested at 1 A g –1 , its specific capacitance reaches 313.4 F g –1 . Furthermore, MnO 2 @NSPC demonstrates outstanding cycling stability. After 25,000 cycles at 10 A g –1 , it can maintain 97.9% of its initial capacity. This study highlights the exceptional ion diffusion kinetics enabled by the introduction of carbon sphere substrates, thereby effectively enhancing the material’s electrochemical performance.