Structural and Electrochemical Properties of Manganese-Doped Tin Disulfide for High- Performance Supercapacitor Applications

Manganese (Mn)-doped tin disulfide (SnS₂) nanoparticles with varying Mn concentrations (2, 4, 6, and 8%) were synthesized using a facile solvothermal method and characterized for their potential application in supercapacitors. X-ray diffraction analysis (XRD) verified the successful integration of Mn into the SnS₂ structure, without the emergence of distinct phases. Scanning electron microscopy (SEM) revealed that the 6% Mn-doped sample (MN6) exhibited a well-defined rod- like morphology with interconnected nanosheets, providing a large surface area. Brunauer- Emmett-Teller (BET) analysis showed that MN6 had a specific surface area of 46.742 m² g⁻¹ and a pore volume of 0.054 cc g⁻¹. Electrochemical measurements in a three-electrode configuration demonstrated that MN6 exhibited the best performance, with a specific capacitance of 822.85 F/g at 2 A/g, which is superior to other doping concentrations. In a two-electrode asymmetric supercapacitor device, MN6 achieved a specific capacitance of 774.13 F/g at 2 A/g, an energy density of 387.06 Wh kg⁻¹, and a power density of 1.2 kW kg⁻¹. The device also exhibited remarkable cyclic stability, maintaining 93.5% of its initial capacitance after 2000 cycles. These results highlight the potential of Mn-doped SnS₂, particularly MN6, as an electrode material for high- performance supercapacitors.