Activated carbon derived from oleander seeds supported ceria-zirconia mixed oxides for enhanced supercapacitive behaviour

Abstract

Oxides of metals in combination with large surface area carbons have considered as a top contender for energy storage systems. In similar line, the present study explores the utilisation of a bi-metallic mixed oxide with activated carbon generated from biological sources as a promising electrode material for supercapacitor applications. The combination of activated carbon synthesized from the seeds of an Oleander plant that is readily available in North-east India, and the bimetallic mixed oxide (ceria-zirconia) synthesized through a conventional co-precipitation process is observed to have a specific capacitance of 270 F/g (at 1 A/g) and cycling stability with 98 % retention of specific capacitance up to 10,000 cycles. The produced electrode materials were characterised using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). All the analyses revealed that the synthesized materials have the potential to be used as supercapacitor electrodes.