Fabrication and electrochemical performance of MXene/carbon nanotubes/tungsten oxide-based nanocomposite

초록

MXene-based materials have attracted significant attention as next-generation electrode materials for supercapacitors due to their metallic conductivity, tunable surface chemistry, and high volumetric capacitance. However, their electrochemical performance is often limited by nanosheet restacking and sluggish ion transport, which restricts access to the active surface. To address these limitations, a Ti3C2Tx MXene-based ternary composite incorporating intercalated carbon nanotubes (CNTs) and tungsten oxide (WO3) nanostructures (MX-CNT-WO3) was developed, and the CNT and WO3 contents were systematically optimized (3, 5, and 7 wt%) to achieve enhanced charge-storage performance. CNTs incorporation prevents MXene restacking, exposes basal planes for ion access, and forms conductive networks that accelerate electron transport, thereby enhancing rate capability. Meanwhile, the inclusion of WO3 introduces additional redox-active sites and expands the interlayer spacing, improving ion accessibility and overall charge storage capacity. Electrochemical evaluation in 1 M H2SO4 electrolyte demonstrated that the MX-CNT-WO3 (5 wt%) electrode achieved a specific capacitance of similar to 320 F g(-1), significantly higher than pristine MXene (similar to 229 F g(-1)), with better rate capability and capacitive retention even at high scan rates. The hybrid electrode also delivered an energy density of similar to 12 Wh kg(-1) at a power density of 7.3 kW kg(-1), highlighting the synergistic effects of CNT and WO3 intercalation. The MX-CNT-WO3 electrode-based device retains similar to 80% capacitance after 10,000 cycles at 10 A g(-1) with similar to 100% coulombic efficiency, indicating good reversibility despite minor structural degradation.

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