Ion-intercalation regulation of MXene-derived hydrated vanadates for high-rate and long-life Zn-Ion batteries

Vanadium oxides are promising cathode materials for Zn-ion batteries (ZIBs) because of their high electrochemical performance. However, its low conductivity remains to be the major obstacle for further utilization. Even the conventional introduction of conductive substrate cannot maintain the structural stability of the composite during cycling. Herein, a universal strategy is proposed to fabricate high-rate cathodes by rationally designing the heterostructure through one-step ion intercalation and phase transition of MXene-derived hydrated vanadates. The hydrated vanadate inherits the intrinsic conductivity from MXene, which can promote faster Zn2+ diffusion kinetics. Therefore, Mn2+-intercalated V10O24.nH2O derived from V2CTx as the prototype cathode material shows superior rate capacity and cycling stability (289.6 mAh g−1 at 10 A g−1 after 25,000 cycles with 92.9% retention). Furthermore, the derivatization strategy is extended to Li+ and Al3+ intercalated hydrated vanadates, which also present excellent electrochemical performances. Successful extension indicates that the concept not only presents a blueprint for the development of robust multi-valent ion batteries but also can be generalized to fabricate varied MXene derivatives for wider applications.