Hierarchical Integration of MoS₂ Nanoflower /MnO₂ Nanorod/CNT Ternary Composite Electrode for High Capacitance and Long Term Cyclic Stability

Abstract

MoS₂ nanoflowers provide abundant active sites for charge storage but suffer from low conductivity, sheet restacking, and cycling degradation. MnO₂ nanorods add pronounced pseudocapacitance yet undergo volumetric changes and sluggish charge transport. To integrate high capacitance, conductivity, and stability in this study, we first optimized MoS₂/MnO₂ binaries with varying MnO₂ loadings, then introduced 1 wt% CNTs via a facile hydrothermal route. The CNTs form a flexible, highly conductive network that accelerates electron/ion transport and reinforces structural integrity. The resulting MoS₂/MnO₂/CNT ternary composite delivers enhanced pseudocapacitance, rate capability, and long-term cycling stability for supercapacitor electrodes. XRD and SEM investigations indicate that the incorporation of MnO₂ nanorods and CNTs facilitates the formation of smaller, defect-laden 3D MoS₂ structures with increased surface area, enhancing ion mobility and exposing more active sites. XPS verifies strong interactions and surface alterations, demonstrating that the composite exhibits useful defects. Electrochemical characterization, performed in 1 M KOH, revealed that EIS and CV measurements of MoS₂ /MnO₂ (5 wt%)/CNT (1 wt%) electrode showed significantly reduced resistance and enhanced current response and capacitance, enabling rapid charge transfer. The ternary composite electrode demonstrated an impressive specific capacitance of 457 F·g⁻¹ at 0.15 A·g⁻¹, with 96% capacitance retention and 100% coulombic efficiency over 2,000 cycles. It also delivered an energy density of 37 Wh·kg⁻¹ while maintaining excellent electrochemical stability. The synergistic interaction among the components creates a defect-rich, highly conductive, and structurally stable framework with low charge-transfer resistance and strong cycling durability, positioning the composite as a promising candidate for high-performance energy storage and renewable energy applications.

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