Effect of “Mn” substitution at B-site, on the crystal structure and energy storage performance of the La_0.75Sr_0.25CoO₃ perovskite

This study explores the potential of redox-active electrode materials to address challenges in high-energy–density batteries and supercapacitor devices, including limited cyclic stability, slow charge storage kinetics, and low electrical conductivity. The investigation focuses on perovskite oxide-based electrodes, known for their compositional flexibility and structural stability, as a promising solution. Lanthanum-based perovskites, synthesized via the sol–gel combustion method, underwent comprehensive analysis, varying manganese (Mn) content from 0.25 to 0.75. Through X-ray diffraction, Rietveld analysis, scanning and transmission electron microscopy, energy dispersive X-ray analysis, and galvanometric potentiostat techniques, the effects of Mn-substitution at the B-site on structural, morphological, electron densities, and electrochemical behavior were thoroughly examined. La_0.75Sr_0.25Co_0.5Mn_0.5O₃ (LCM-2) emerged as a stable variant with low internal strains, exhibiting the highest specific capacity (713C/g at a 2 mV/s scan rate) among all perovskite samples. Notably, LCM-2 perovskite displayed low electron density, which is attributed to oxygen deficiency, indicating its potential for application in highly energy-dense electrochemical energy storage devices. This research contributes valuable insights for advancing the development and commercialization of efficient energy storage technologies.