Binder free high performance hybrid supercapacitor device based on nickel ferrite nanoparticles

In this study, we present the actual electrochemical performance of a highly stable hybrid supercapacitor device based on faradic type binder free nickel ferrite (NiFe2O4) positive electrode and activated carbon negative electrode. NiFe2O4 nanoparticles are directly grown over the Ni-foam and stainless steel substrates by a scalable and novel surfactant assisted co-precipitation technique. The structural and morphological properties of the NiFe2O4 nanoparticles are investigated by using different characterization techniques. The electrochemical performance is investigated in 6 M aqueous KOH electrolyte using cyclic voltammetry and galvanostatic charge-discharge techniques. Ni-foam/NiFe2O4 positive electrode exhibits specific capacity of 398 C/g at 1 A/g current density which is much higher than the stainless steel /NiFe2O4 positive electrodes and can be attributed to the better interfacial bonding between Ni-foam and NiFe2O4 nanoparticles and formation of a concomitant 3D porous architecture. A maximum specific energy of 27.71 Wh/kg and specific power of 14.49 kW/kg are achieved at 1 and 20 A/g current density in the hybrid supercapacitor device fabricated utilizing the Ni-foam/ NiFe2O4 positive and activated carbon negetive electrodes. Moreover, the device shows similar to 98% retention of its specific capacity after 6500 cycles at 5 A/g current density which reveals superiority of NiFe2O4 as an electrode material for supercapacitor application.