Evaluation of Fe and Cr-Doped Zinc Cobaltite in Symmetric and Asymmetric Supercapacitor

Cobaltite with a spinel structure as an electrode offers great potential for specific kinds of supercapacitor technology. In the present work, the Fe,Cr:ZnCo2O4 is achieved by the facile sol–gel method and is reported for the first time. Half cell constructed with Fe,Cr:ZnCo2O4 as an electrode with platinum as a counter electrode has shown a specific capacitance value of 320 Fg−1 with 1 M KOH electrolytic solution. To explore the influence of Fe,Cr:ZnCo2O4 on the full-cell performance, systematic research is carried out by constructing both symmetric and asymmetric devices. The symmetric supercapacitor employing Fe,Cr:ZnCo2O4 as both electrodes exhibited an areal energy density of 16 µWh/cm2 and a power density of 1200 µW/cm2. Carbon prepared, from plasma firing of Prosopis juliflora (P-Carbon), already reported1 is utilized as a counter electrode for asymmetric devices that resulted in an areal energy density of 34.7 µWh/cm2 and a power density of 2842 µW/cm2. The asymmetric devices showed a capacity retention of 85% on long-term cycling. The results are discussed in detail in the full paper.