Electrochemical Material Processing via Continuous Charge-Discharge Cycling: Enhanced Performance upon Cycling for Porous LaMnO3 Perovskite Supercapacitor Electrodes

Creating controlled porous morphologies in smart materials offers a significant enhancement in their properties, which can not only open access to various applications, but also improve their efficiency and performance. Among smart materials, porous carbon electrodes have been receiving much attention owing to their smooth and faster ionic kinetics in regard to their electrode-electrolyte interface, which is promising for the development of high performance devices with a prolonged lifetime. Various techniques including soft and hard templating approaches are available for controlling the pore structure and morphological control of these porous carbon nanostructures, used as negative electrodes. However, reports on stable porous positive electrodes are quite limited. Here, we report on porous LaMnO3 electrodes and their application in symmetric supercapacitors exhibiting high energy and power densities over prolonged lifetime (>110,000 cycles). We demonstrate that a simple electrochemical cycling process can be used as an efficient tool to create proper channels by interconnecting the adjacent pores of the porous electrode material to facilitate smooth and faster ionic transport or intercalation/deintercalation of electrolyte species into the electrode surface. The creation of channels and preconditioning of the electrode surface are well investigated by analysing the voltammogram at various cycles and supports the enhancement of the supercapacitance even after myriad cycles.