Performance of asymmetric supercapacitor fabricated with perovskite‐type Sr <sup>2+</sup> ‐incorporated <scp> LaMnO <sub>3</sub> </scp> (La <sub>0.</sub> <scp> <sub>7</sub> Sr <sub>0</sub> </scp> <sub>.</sub> <scp> <sub>3</sub> MnO <sub>3</sub> </scp> ) nanostructures in neutral <scp> 1M Na <sub>2</sub> SO <sub>4</sub> </scp> aqueous electrolyte
Atanu Roy, Francisco Enrique Cancino‐Gordillo, Samik Saha, Umapada Pal, Sachindranath Das
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.