Impact of Ca ions substitution at A-site on LaCoO3 perovskite energy applications

Lanthanide-based perovskites are promising candidates for supercapacitor applications due to their high crystallinity, reversible redox capabilities, diverse electrical properties, oxygen-rich vacancies, stable structures, ease of synthesis, and cost-effectiveness. This study synthesized La_1-xCa_xCoO₃ (x = 0, 0.1, 0.15, and 0.2) samples using the sol–gel method. The La_0.85Ca_0.15CoO₃ sample shows a charge transfer resistance of 0.68 Ω and a specific surface area of 44.52 m²/g. The La_0.85Ca_0.15CoO₃ sample exhibits a specific capacitance of 284.4F/g at a current density of 1 A/g, which is 3.38 times greater than that of the intrinsic sample. The charge storage mechanism involving the oxygen anions was explored through an overcharge and discharge process, revealing that elemental Ca doping markedly enhances the charge storage capacity associated with oxygen intercalation in the LaCoO₃ system. These results suggest that Ca-substituted A-site of perovskites possess significant potential for supercapacitor applications.