Insights into mixed metal sulfides of MnxSn1-xS2 for high-performance supercapacitors

Abstract

• Substitutional solid solution Mn x Sn 1-x S 2 can be easily synthesized. • Mn 0.33 Sn 0.67 S 2 delivers the highest capacitance electrochemical performances. • The content of Mn plays a crucial role in the lattice parameter and electrochemical properties. • Mn 0.33 Sn 0.67 S 2 //AC achieves excellent energy density of 15.68 Wh kg −1 at 0.15 kW kg −1 . A variety of mixed metal sulfides of Mn x Sn 1-x S 2 nanoflowers were synthesized by a facile one-step template-free solvothermal method and their ability of capacitive energy storage were evaluated as potential supercapacitor electrode materials. Substitutional solid solutions of Mn x Sn 1-x S 2 with various chemical compositions can easily be produced by varying the Mn/Sn molar ratio in the reactants. Among these sulfides, Mn 0.33 Sn 0.67 S 2 exhibits the highest electrochemical performance with a high specific capacitance of 1118.92 F g −1 at 1 A g −1 , great rate capacity and superb cycling stability. Because of its increased electrochemical active sites, altered microstructure, and improved electrical conductivity brought on by lattice distortion and the synergistic effect of elemental substitution, Mn 0.33 Sn 0.67 S 2 exhibits good performance. What’s more, an asymmetric supercapacitor of Mn 0.33 Sn 0.67 S 2 //AC (activated carbon) possesses a high energy density (15.68 Wh kg −1 at 150.1 W kg −1 ). Thus, Mn doped tin sulfides highlight widely applicable to advance high-performance energy storage technology.