Development of binder–free Ni3S2/CoS2 nano–composite as electrode material for energy storage application

Global energy crisis imposes immense obstacles leading towards development of innovative devices, and supercapacitors (SCs) are thought to be a viable energy storage technology. The engineering of nanostructured materials with a distinct and consistent morphological design is seen as a better option for various range of electrochemical energy sources. This study reports novel binder-free Ni₃S₂/CoS₂ electrode material that acquires higher energy, higher energy density, as well as its simple preparation method, low cost, and earth–abundant resources. The morphological, structural, and textural characteristics resulted in surface area of 46 m² g⁻¹ of Ni₃S₂/CoS₂ that will increase active sites also. The synthesized nanocomposite has particle size of 41.1 nm that leads to enhanced active sites and greater surface area as confirmed through BET analysis. Ni₃S₂/CoS₂ nanocomposite has high specific capacity around 828.14 F g⁻¹ at 5 mV s⁻¹ sweep rate using 2 M KOH, a high energy density around 115.01 Wh kg⁻¹, and power density of 1000 Wh kg⁻¹. Ni₃S₂/CoS₂ acquires higher ionic conductivity of 5 S m⁻¹, this will enhance the inter-layer transference of electrons, and these results perfectly correlates with EIS, resulting in charge transfer resistance value of 0.9 Ω for nano-composite. These enhanced electrochemical capabilities of Ni₃S₂/CoS₂ hold significant potential in practical viability.