Ti3C2Tx MXene: An all-rounder material for next-generation solid-state batteries

2D MXenes, particularly Ti3C2Tx, have emerged as promising multifunctional materials for advancing solid-state batteries (SSBs). While SSBs offer superior safety and energy density over liquid-electrolyte systems, critical challenges such as interfacial resistance, limited ion transport, dendrite growth, and mechanical degradation hinder their widespread adoption. This review aims to provide a comprehensive analysis of the roles and functions of Ti3C2Tx MXenes in SSBs, emphasizing their application as interlayers, anode/cathode additives, and current collectors, and highlighting their impact on interfacial stability, ionic/electronic transport, electrochemical performance, and cycling durability in SSB architectures. Unlike other 2D materials, Ti3C2Tx exhibits outstanding metallic conductivity, tunable surface terminations, hydrophilicity, and excellent mechanical flexibility, making it ideal for multifunctional integration in SSBs. As a component in solid-state electrolytes (SSEs), Ti3C2Tx improves ionic conductivity and mechanical strength. When used in electrodes, it serves as a conductive scaffold that enhances charge transport and structural durability. Additionally, its role as an interfacial interlayer effectively reduces interfacial impedance, accommodates volume changes, and suppresses dendrite formation. Its lightweight and high conductivity enable its use as a current collector. This review highlights recent advances in Ti3C2Tx-based components for SSBs like Li-, Na-, Zn, Li-S, etc., emphasizing enhancements in ion/electron transport, interfacial stability, and structural robustness. Finally, the review outlines challenges and opportunities along with a future outlook focused on improving the MXene oxidation, tailoring surface terminations, improving long-term stability, and exploring scalable fabrication strategies for MXene-based SSB components.