Manganese sulfide (MnS) has received attention as an outstanding electrode material for supercapacitors, demonstrating high theoretical capacitance, environmental safety, lower production costs, and superior conductivity. Among its phases, α-MnS is the best phase for supercapacitors because of its cubic structure, which remains stable during long-term use and withstands degradation effectively. Moreover, the addition of minimal hexagonal γ-MnS phase functions as an ion transfer pathway, accelerating the overall conductivity. The combination of α-MnS for stability and γ-MnS for ion transfer produces an electrode with improved electrochemical performance. To achieve MnS nanoparticles with a dominant α-phase and minor γ-phase, this study employed the binary solvent-assisted solvothermal method and optimized it at different temperatures and durations. The optimized MnS electrode displayed a higher specific capacitance of 237 F/g at a current density of 0.5 A/g and 87% capacitive retention over 500 cycles. The MnS symmetric supercapacitor (SSC) achieved 28 F/g at 0.5 A/g with an excellent capacity retention rate of 117%. The LED powered by four symmetric cells for 8 min indicates the practical application of supercapacitors in real-world applications.
S et al. (2026) studied this question.