Hydrothermal-deposition synthesis of MnO2/MnS nanorods as high-performance asymmetric supercapacitor positive electrode materials

Nanostructuring has shown promise in enhancing the performance of MnO₂ for energy storage in supercapacitors, highlighting its technological significance. This study introduces an innovative synthesis method, employing hydrothermal and constant-pressure deposition techniques, to produce nanostructured MnO₂/MnS rod electrodes on nickel foam. The roded heterostructure enhances specific surface area, conductivity, and symbiotic effect between MnO₂ and MnS. With optimized material and structural advantages, the electrode reaches a capacitance of 977.6 ​F ​g⁻¹ at 1 ​A ​g⁻¹, demonstrating extended cycling lifespan. Using MnO₂/MnS-5h rods as the positive electrode and activated carbon as the negative electrode, the supercapacitor achieves an energy density of 122.23 ​Wh kg⁻¹ at 898.75 ​W ​kg⁻¹. Notably, it maintains 91.55 ​% capacity retention after 5000 cycles at 10 ​A ​g⁻¹, indicating outstanding cycling stability. This research presents a promising solution for efficient energy storage, emphasizing the potential application of the developed MnO₂/MnS based supercapacitor in high-performance energy storage systems.