Synthesis and electrochemical properties of nanostructured binder-free MgS–NiS as electrode material for supercapacitor applications

The worldwide energy crisis imposes massive complications leading towards the growth of revolutionary devices, amid them the supercapacitors and batteries are supposed to be based on sustainable energy storage technology. The engineering of nanostructured materials with porous surface morphologies and binder-free synthesis of novel nanostructured electrode materials (EMs) is a better option for electrochemical energy sources. This study reports the synthesis of innovative binder-free MgS–NiS EMs (containing weight%: Ni = 45.6, S = 18.3 and Mg = 36.1 %) that acquires high energy density (42 Wh/kg), high power density (2048 W/kg), high specific capacities (4317 F/g at 0.5 mV/s), good capacity retention (96 %), high Coulombic efficiency (100 %) and excellent cyclic stability even after 20000 cycles via a simple home-made chemical vapor deposition technique. The structural and morphological properties resulted in surface area of 105.17 m²/g and pore size of 6.9 nm of MgS–NiS EMs that increases the active sites results in the increase of electrochemical performance. The redox reactions occurred in MgS–NiS EMs are controlled by diffusive controlled contribution at lower scan rates while such redox reactions are controlled by capacitive controlled contribution at higher scan rates. The achievement of smaller charge transfer resistance (negligibly small semicircle formation) indicates the high conductivity of MgS–NiS EMs that will enhance the inter-layer transference of electrons. Such enhanced electrochemical capabilities of MgS–NiS EMs hold considerable potential in functional practicability.