Enhanced Electrochemical Performance of LaMnO<sub>3</sub>-Co<sub>3</sub>O<sub>4</sub> nanocomposite for Energy Storage.
ORAL
Abstract
The perovskite oxide LaMnO3 and metal oxide Co3O4 are gaining significant attention as a sustainable energy storage system. LaMnO3±δ, with oxygen-ion intercalation capability, enables rapid energy storage and is an effective supercapacitor material. Meanwhile, Co3O4 benefits from the multiple oxidation states of manganese, enhancing its pseudocapacitance through faradic processes. However, the poor electrical conductivity and structural stability of the Co3O4 material limit their practical use as an electrode material for energy storage devices. To address these limitations LaMnO3-Co3O4 composite samples (9:1,7:3,1:1) were prepared via autocombustion method followed by calcination at 800 OC. The X-ray diffraction analysis confirms the presence of individual compounds in the desired ratio. The chemical composition of composites was determined by x-ray photoelectron spectroscopy (XPS). The presence of Mn2+, Mn3+, and Mn4+ and Co2+ and Co3+ oxidation states revealed the presence of both LaMnO3 and Co3O4 in the composite.
The electrochemical performance of the composite electrodes, fabricated on nickel foam and tested in 1M KOH solution, showed that the composites generally exhibited higher specific capacitance than the pure compounds, except for the LMO-Co3O4 (50%: 50%) composites. LMO-Co3O4 (70%: 30%) composites demonstrated a particularly high specific capacitance of approximately 805 F/g at a scan rate of 1 mV/s, which decreased with higher Co3O4 content. This composite also achieved a specific capacitance of 658 F/g, with an energy density of 32 Wh/kg and a power density of 202 W/kg at a current density of 0.5 A/g in a 1M KOH electrolyte.
The improved performance of the LaMnO3-Co3O4 composites could be attributed to reduced internal resistance, facilitated reversible faradic processes at the interface, and high Coulombic efficiency. Enhanced charge transfer kinetics at the electrode-electrolyte interface and easy electron hopping between LaMnO3 (electron donor) and Co3O4 (electron acceptor) likely contribute to the increased energy density, power density, and specific capacitance. These findings are significant for developing high-energy supercapacitor devices using this new composite as an electrode material.
Authors: A. Dhakal, Dr. Felio A Perez, Dr. S. R. Mishra
The electrochemical performance of the composite electrodes, fabricated on nickel foam and tested in 1M KOH solution, showed that the composites generally exhibited higher specific capacitance than the pure compounds, except for the LMO-Co3O4 (50%: 50%) composites. LMO-Co3O4 (70%: 30%) composites demonstrated a particularly high specific capacitance of approximately 805 F/g at a scan rate of 1 mV/s, which decreased with higher Co3O4 content. This composite also achieved a specific capacitance of 658 F/g, with an energy density of 32 Wh/kg and a power density of 202 W/kg at a current density of 0.5 A/g in a 1M KOH electrolyte.
The improved performance of the LaMnO3-Co3O4 composites could be attributed to reduced internal resistance, facilitated reversible faradic processes at the interface, and high Coulombic efficiency. Enhanced charge transfer kinetics at the electrode-electrolyte interface and easy electron hopping between LaMnO3 (electron donor) and Co3O4 (electron acceptor) likely contribute to the increased energy density, power density, and specific capacitance. These findings are significant for developing high-energy supercapacitor devices using this new composite as an electrode material.
Authors: A. Dhakal, Dr. Felio A Perez, Dr. S. R. Mishra
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Presenters
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Alisha Dhakal
University of Memphis
Authors
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Alisha Dhakal
University of Memphis