Double transition metal Ti2NbC2Tx MXene with modulated electronic structure for advanced lithium-ion capacitors

作者：Yunfeng Guan, Sheng Zhou, Lidan Tan, Rong Zhao, Qin Zhang, Hui Zhu, Xuanke Li, Zhijun Dong, Haiyan Duan, Dunzhu Li, Valeria Nicolosi, Ye Cong, Ke Li · 发表于：Energy storage materials · 年份：2025 · DOI：10.1016/j.ensm.2025.104032 · 被引用次数：27 · 研究领域：MXene and MAX Phase Materials、Ferroelectric and Negative Capacitance Devices、2D Materials and Applications

Double transition metal (DTM) MXenes are garnering increasing attention owe to their wide diversity, controllable properties, tunable electronic structure and surface chemistry. Nevertheless, research on the exciting DTM MXenes is still in its infancy. Herein, we present a novel out-of-plan ordered DTM MXene, Ti 2 NbC 2 T x , achieved by introducing Nb species into the M (Ti) site of Ti 3 C 2 T x MXene. In which, Ti and Nb atoms occupy the outer and middle transition metal layers, respectively. This structure endows the as-synthesized Ti 2 NbC 2 T x MXene with significantly higher chemical affinity and absorbability for lithium ions than Ti 3 C 2 T x , showing a high reversible capacity of up to 272 mAh g -1 at 0.1 A g -1 and exceptional long-term stability (no capacity loss after 1000 cycles). Moreover, the lithium-ion capacitors (LICs) assembled with Ti 2 NbC 2 T x MXene anode and activated carbon (AC) cathode exhibit high energy and power densities of 39 Wh Kg -1 and 4600 W kg -1 , respectively, surpassing the most state-of-the-art MXene-based LICs. This work demonstrates the significant potential of DTM MXenes in advancing energy storage applications. An out-of-plane ordered double transition metal Ti 2 NbC 2 T x MXene with modulated electronic structure was successfully synthesized by introducing Nb into Ti 3 C 2 T x MXene via an alloy engineering strategy. This structure endows the synthesized Ti 2 NbC 2 T x MXene with significantly higher lithium-ion chemical affinity/...