MXene-based nanomaterials for high-performance supercapacitors

Ti₃C₂Tₓ, a prominent member of the MXene family, has emerged as a highly promising two-dimensional electrode material for supercapacitors due to its exceptional metallic conductivity, hydrophilicity, and abundant surface-active sites that support rapid redox reactions. However, despite its advantageous properties, several intrinsic challenges, such as structural restacking, surface re-crushing, and titanium oxidation, continue to limit its achievable specific capacitance and long-term cycling performance. Recent research has focused on addressing these limitations through strategies aimed at improving ion accessibility, stability, and charge storage efficiency. This review provides a comprehensive analysis and comparison of major enhancement approaches, including film engineering, surface termination modification, interlayer spacing regulation, and the development of Ti₃C₂Tₓ-based composite architectures. Furthermore, the electrochemical mechanisms governing energy storage are examined across different electrolyte systems, highlighting the influence of ion size, transport behavior, and interfacial interactions. The insights presented herein offer a systematic understanding of performance-boosting strategies and aim to guide future advancements in the design and optimization of Ti₃C₂Tₓ MXenes for next-generation, high-performance supercapacitors.