Flexible Supercapacitor Electrodes Based on Carbon Cloth-Supported LaMnO3/MnO Nano-Arrays by One-Step Electrodeposition

Abstract

La-based perovskite-type oxide is a new type of supercapacitor electrode material with great potential. In the present study, LaMnO₃/MnO (LMO/MnO) nano-arrays supported by carbon cloth are prepared via a simple one-step electrodeposition as flexible supercapacitor electrodes. The structure, deposit morphology of LMO/MnO, and the corresponding electrochemical properties have been investigated in detail. Carbon cloth-supported LMO/MnO electrode exhibits a specific capacitance of 260 F·g^-1 at a current density of 0.5 A·g^-1 in 0.5 M Na₂SO₄ aqueous electrolyte solution. The cooperative effects of LMO and MnO, as well as the uniform nano-array morphology contribute to the good electrochemical performance. In addition, a symmetric supercapacitor with a wide voltage window of 2 V is fabricated, showing a high energy density of 28.15 Wh·kg^-1 at a power density of 745 W·kg^-1. The specific capacitance drops to 65% retention after the first 500 cycles due to the element leaching effect and partial flaking of LMO/MnO, yet remains stable until 5000 cycles. It is the first time that La-based perovskite has been exploited for flexible supercapacitor applications, and further optimization is expected.