The large scale energy production and developments in renewable energy sources requires efficient energy storage systems. The physical and chemical charge storage techniques along with high power and energy density brought electrochemical supercapacitors (ECs) as a versatile power source. The high rates of charging and discharging with long cycle life as well as the economical and eco-friendly nature support ECs to various energy applications.  Since the last couple of decades, Supercapacitors with various metal oxides as electrode materials got a great interest among researchers. Here we synthesised α-MnO₂ nanoparticles by simple chemical precipitation method and are subjected to heat treatment at 300 ˚C, 500 ˚C and 700 ˚C. The structural formation of as- prepared and annealed MnO₂ are confirmed by XRD analysis. The functional group and optical absorption studies are done by Fourier transform infrared spectroscopy (FTIR) and UV visible spectroscopy. The surface area of the samples is measured using Brunauer-Emmett-Teller (BET) method. Finally electrochemical properties are evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge techniques. The cyclic voltammogram and charge-discharge curve recorded indicates MnO₂ nanoparticles annealed at 300 ˚C for 5 h shows better electrochemical behaviour.