Performance of asymmetric supercapacitor fabricated with perovskite‐type Sr 2+ ‐incorporated LaMnO 3 (La 0. 7 Sr 0 . 3 MnO 3 ) nanostructures in neutral 1M Na 2 SO 4 aqueous electrolyte

Abstract

Strontium (Sr) incorporated LaMnO3 (La0.7Sr0.3MnO3) nanoparticles have been synthesized by ball-milling-assisted solid-state reaction to study their performance as electrode material for energy storage applications. The La0.7Sr0.3MnO3 nanoparticles exhibit superior electrochemical performance in neutral aqueous electrolyte (1 M Na2SO4) in comparison to LaMnO3 and SrMnO3 nanoparticles. This neutral electrolyte provides relatively higher ionic conductivity and viscosity compared to the ionic liquids and a wider potential window compared to the alkaline electrolytes. Electrochemical study of the electrodes prepared using La0.7Sr0.3MnO3 nanoparticles reveals pseudocapacitive behaviors with fast reversible Faradaic charge storage, which plays a key role in charge storage. The composite materials exhibit highest specific capacitance of 393.5 F g−1 at a scan rate of 2 mV s−1. Asymmetric supercapacitors fabricated using La0.7Sr0.3MnO3 nanoparticle and activated carbon operates over a wide potential window of 1.8 V, and it reveals high specific capacitance (197 F g−1) as well as high capacitive retention (87%) even after 4000 charge–discharge cycles.