Ternary Nanohybrid of Ni3S2/CoMoS4/MnO2 on Nickel Foam for Aqueous and Solid-State High-Performance Supercapacitors

To overcome the issues related to supercapacitor (SC) electrodes, such as high cost, low specific capacitance (C-s), low energy density (ED), requirements for expensive binder, etc., binderless electrodes are highly desirable. Here, a new ternary nanohybrid is presented as a binder-free SC electrode based on Ni3S2, CoMoS4, and MnO2. A facile two-step hydrothermal route, followed by a short thermal annealing process, is developed to grow amorphous polyhedral structured CoMoS4 and further wrap MnO2 nanowires on Ni foam. This rationally designed binder-free electrode exhibited the highest C-s of 2021 F g(-1) (specific capacity of 883.8 C g(-1) or 245.5 mAh g(-1)) at a current density of 1 A g(-1) in 1 M KOH electrolyte with a highly porous surface morphology. This electrode material exhibited excellent cycling stability (90% capacitance retention after 4000 cycles) due to the synergistic contribution of individual components and advanced surface properties. Furthermore, an aqueous binder-free asymmetric SC based on this ternary composite exhibited an ED of 20.7 Wh kg(-1), whereas a solid-state asymmetric SC achieved an ED of 13.8 Wh kg(-1). This nanohybrid can be considered a promising binder-free electrode for both aqueous and solid-state asymmetric SCs with these remarkable electrochemical properties.

Automated summary

A new ternary nanohybrid has been developed as a binder-free supercapacitor electrode, exhibiting high specific capacitance, high energy density, and excellent cycling stability.