Two-step in-situ hydrothermal synthesis of nanosheet-constructed porous MnMoS4 arrays on 3D Ni foam as a binder-free electrode in high-performance supercapacitors

Synthesis and electrochemical properties of nanocubes Mn2SnS3 for high-performance supercapacitors

Exploring environment-friendly active material-electrolyte combinations has become increasingly necessary with the rising use of supercapacitors. In this study, the potential of ternary Mn2SnS3 on Ni foam as an electrode material was considered. The study investigated the impact of precursors on the morphology of the prepared electrodes utilizing techniques such as X-ray diffraction, energy dispersive X-ray analysis, field-emission scanning electron microscopy, and transmission electron microscopy. Nanocubes Mn2SnS3 (NC-MTS) and nanoworms Mn2SnS3 (NW-MTS) were synthesized via a facile solvothermal route. The results suggest that NC-MTS exhibits better capacitive performance compared with NW-MTS, which means that morphology has a significant effect on the electrochemical reaction. NC-MTS presents excellent supercapacitor performances with a high specific capacity of about 2115 F g-1 at current density 2 A g-1, excellent rate capability of 78% at 17 A g-1 and excellent cycling stability 92% capacitance retention after 3000 GCD cycles. Whereas, NW-MTS illustrated a specific capacity of about 853 F g-1 at current density 2 A g-1, rate capability of 50% at 17 A g-1 and cycling stability of 81% capacitance retention after 3000 GCD cycles. Additionally, an asymmetric supercapacitor NC-MTS/NF//AC based on the NC-MTS/NF as a positive electrode and activated carbon (AC) as a negative electrode was successfully constructed with the excellent electrochemical performance, which demonstrated a high energy density of 60.56 Wh kg-1 and a high power density of 699.89 W kg-1.

MnMoO4-S nanosheets with rich oxygen vacancies for high-performance supercapacitors

The structure of materials is closely related to their electrochemical properties. MnMoO₄ materials have good stability as supercapacitors but their specific capacitance performance is not excellent. To improve electrochemical performance of MnMoO₄, this study conducts secondary hydrothermal treatment in thiourea solution on MnMoO₄ electrode material grown on nickel foam synthesized by traditional hydrothermal method. A more compact S-doped MnMoO₄ electrode material with more oxygen vacancies and higher specific capacitance was obtained. At the current density of 1 A g^-1, the specific capacitance of the composite material reached 2526.7 F g^-1, which increased by 140.9% compared with that of ordinary MnMoO₄ material. The capacitance retention rate of the composite material was 95.56% after 2000 cycles at 10 A g^-1. An asymmetric supercapacitor was fabricated using S-doped MnMoO₄ as the positive electrode, activated carbon as the negative electrode, and 6 mol L^-1 KOH solution as the electrolyte. The specific capacitance of the assembled supercapacitor was 117.50 F g^-1 at 1 A g^-1, and a high energy density of 47.16 W h kg^-1 at the power density of 849.98 W kg^-1 was recorded. This method greatly improves the specific capacitance of MnMoO₄ through simple processing, which makes it have great application potential.

In situ synthesis of advantageously united copper stannate nanoparticles for a new high powered supercapacitor electrode

A novel CuNi2O4@SnS@rGO/NF multicomponent hybrid material leads to fast ion/electron transfers at the electrode/electrolyte interface.