TiNbC MXene cathode for high-performance aluminum-ion batteries

Abstract Al-ion batteries (AIBs) have emerged as a promising energy storage technology due to their high theoretical capacity, cost-effectiveness, and superior safety. However, the lack of stable and efficient cathode materials capable of reversible Al-complex ion (e.g., [AlCl4]−) insertion/extraction remains a critical challenge. In this work, we developed TiNbCT x MXene as a high-performance cathode material for AIBs, achieving remarkable capacity and cycling stability. Unlike symmetric-structured Ti2CT x , the TiNbCT x cathode leverages synergistic Ti–Nb bimetallic effects to enhance the electronic conductivity and electrochemical activity. Here we show, TiNbCT x delivers a high reversible capacity of 194 mAh·g−1 at 0.2 A·g−1 with 800-cycle stability. Through combined experimental characterization and density functional theory (DFT) calculations, we elucidate the kinetic mechanisms of energy storage, offering fundamental insights for the rational design of advanced cathode materials in AIBs.