Performance Evaluation of MXene-Based Nanocomposites for Advanced Energy Storage

Abstract

The escalating global demand for high-performance energy storage systems has catalyzed intensive research into two-dimensional (2D) nanomaterials that bridge the performance gap between conventional batteries and supercapacitors. Among emerging 2D materials, MXenes — a family of transition metal carbides, nitrides, and carbonitrides — have distinguished themselves through exceptional metallic conductivity, hydrophilic surface chemistry, and tunable interlayer spacing. This comprehensive review evaluates the performance characteristics of MXene-based nanocomposites across supercapacitor, lithium-ion battery, sodium-ion battery, and zinc-ion hybrid capacitor applications. The study systematically examines synthesis methodologies including hydrofluoric acid etching, minimally invasive layer delamination (MILD), molten salt synthesis, and emerging HF-free routes. Performance metrics encompassing specific capacitance, energy density, power density, cycling stability, and rate capability are critically analyzed for MXene/carbon, MXene/conductive polymer, MXene/metal oxide, MXene/metal sulfide, MXene/layered double hydroxide, and MXene/metal-organic framework composites. The analysis reveals that Ti₃C₂Tₓ-based composites achieve specific capacitances exceeding 1500 F g⁻¹ when hybridized with layered double hydroxides, while MXene/conductive polymer composites demonstrate superior energy densities up to 50.6 Wh L⁻¹. Critical challenges including MXene oxidation susceptibility, restacking phenomena, and scalability constraints are identified. Future research directions emphasize high-entropy MXenes, 3D architectured electrodes, and smart responsive coatings for next-generation energy storage. This review consolidates recent advances and provides a roadmap for rational design of MXene nanocomposites with optimized electrochemical performance.