Engineering Metallenes Integrated with Ti₃C₂T_x MXene 2D/2D Heterointerfaces for Boosted Charge Storage Performance

Two-dimensional (2D) materials have emerged as compelling candidates for next-generation energy storage systems owing to their high surface area, tunable chemistry, quantum confinement, and rapid charge-transfer properties. In this work, we report the synthesis of ultrathin MoBi metallene (MoBiene) via liquid-phase exfoliation and their subsequent integration with delaminated Ti₃C₂T_x MXene to construct a robust 2D/2D hybrid electrode. The heterointerfaces of Metallene into MXene frameworks effectively mitigates nanosheet restacking, enhances electrical conductivity, and increases the density of electroactive sites, thereby improving charge-storage kinetics and mechanical stability. In a three-electrode configuration, the MoBiene/D-MXene hybrid delivers a high specific capacity of 2052.97 F g^-1 (570.26 mAh g^-1) at 1 A g^-1, excellent rate capability and low charge-transfer resistance. Furthermore, an asymmetric supercapacitor assembled with MoBiene/D-MXene as the positive electrode and activated carbon as the negative electrode in aqueous 0.5 M H₂SO₄ operates stably over a wide potential window of 1.5 V, achieving an energy density of 85.02 Wh kg^-1 at a power density of 1116 W kg^-1, along with outstanding cycling stability over 10,000 charge-discharge cycles. Beyond superior electrochemical energy-storage performance, these findings highlight metallene-MXene heterostructures as a rational design strategy for advancing durable, high-performance energy storage technologies.