SYNTHESIS AND CHARACTERIZATION OF MnCo2O4 BASED NANOCOMPOSITE ELECTRODE MATERIALS FOR ASYMMETRIC SUPERCAPACITOR APPLICATION

Abstract

As the global population grows, the demand for energy is increasing exponentially. Historically, fossil fuels have been the primary source of energy worldwide. However, fossil fuels are finite, and their excessive use has led to significant problems, including global warming. So, many scientists have recently shown a strong interest in the production of clean, affordable, and renewable energy due to increasing environmental degradation and energy supply difficulties. Recently, researchers have shown interest in supercapacitors (SCs) as advanced energy storage devices due to their rapid charge/discharge capabilities, higher specific capacitance, high power density, impressive cycling stability, easy handling, low cost, and eco friendly nature. Supercapacitors have high power density but low energy density. They are categorized into three types based on their charge storage methods: electric double-layer capacitors (EDLCs), pseudocapacitors, and hybrid capacitors. EDLCs store charge by forming opposing charge layers at the electrode-electrolyte interface, using carbon materials like activated carbon and graphene. The EDLC method reduces energy density and raises resistance, which limits its efficiency at high currents. Pseudocapacitors use transition metal oxides, polymers, and hydroxides for rapid, reversible redox reactions, which improve specific capacitance and energy density. Hybrid capacitors combine these two techniques. The choice of electrolytes and electrode materials is important for enhancing energy density and stability in supercapacitors. In this regard, binary transition metal oxides (BTMOs) with spinel structure, like MCo2O4 (M = Mn, Co, Ni, Cu, Zn) and MMn2O4 (M = Ni, Co, Zn), have recently attracted a lot of attention because they have larger specific capacitance and reduce activation energy for charge transport. BTMOs are being explored in energy storage for their high theoretical specific capacitances and their ability to undergo diverse oxidation reactions, including redox processes. Among BTMOs, MnCo2O4 has outstanding pseudocapacitive performance due to the synergistic effect of Mn+2 and Co+3 cations.