Effects of Calcium Substitution for La on the Electrochemical Performance of LaMnO 3 Nanoparticles

Abstract With the advantages of short charging and discharging times, high power density, and long cycle life, supercapacitors are regarded as one of the most promising energy storage devices and have garnered massive attention in the field of energy storage. This paper prepared La 1− x Ca x MnO 3 ( x =0, 0.05, 0.1, 0.15, and 0.2) nanoparticles by the sol‐gel method. The microstructure, morphology, and electrochemical performance of the samples were characterized. The results depict that La 0.85 Ca 0.15 MnO 3 has a low charge transfer resistance (0.19 Ω) and a large specific surface area (38.79 m 2 g −1 ). The maximum specific capacitance of the La 0.85 Ca 0.15 MnO 3 sample reached 248 F/g at a current density of 0.5 A/g, which is ascribable to its large specific surface area and high oxygen vacancy concentration. The anion‐intercalation mechanism was investigated by the charging and discharging process. The above results depict that Ca‐doping significantly enhances the electrochemical performance of LaMnO 3 system.