M-site transition metal activation in Mo₂Ti₂C₃T_x MXene for enhanced lithium storage with superior rate performance

Mo₂Ti₂C₃T_x (DM) MXene is a promising energy storage material with rich M-site transition metal components and adjustable structural properties. However, its practical lithium storage capacity remains limited, particularly at high current densities. This study presents a feasible activation strategy for DM MXene, where chemically inert M-X bonds were effectively activated through electrophoretic deposition and annealing treatment, enabling in-situ construction of amorphous transition metal compounds without compromising the layered structure of DM MXene. Compared to pristine DM MXene and activated DM (ADM) materials, the electron and ion transport efficiency of the integrated electrode-hydrophilic carbon nanotube sponges@ADM (HCS@ADM) was significantly enhanced, resulting in a synergistic improvement in its electrochemical performance, particularly in lithium storage capacity and rate performance. As an electrode material for lithium-ion batteries, it delivered a high reversible capacity of 440.0 mAh g^-1 at 10 A g^-1. The activation strategy significantly enhances the electrochemical performance of DM MXene, offering a feasible approach for developing advanced energy storage electrodes.