Promoting Energy Storage Kinetics of Tellurium/Vanadium Selenide Hybrid via Synergistic Intercalation-Conversion Reactions for Aqueous Zinc-Ion Batteries.

Because suitable cathode materials are scarce, the advancement of aqueous zinc-ion batteries (AZIBs) has been seriously hindered. Although intercalation-type compounds offer good cycling stability, they have relatively low specific capacities. On the contrary, conversion-type cathodes can provide higher capacity but often have poor cycle reversibility and stability. Herein, a facile solvothermal approach is employed to prepare the Te/VSe2 hybrid material with Te particles distributed homogeneously on the surface of VSe2 plates. The addition of Te to VSe2 not only boosts significantly the conductivity of the hybrid cathode, promotes fast ion diffusion and electron transport, but also su pplies extra specific capacity. In addition, the introduction of Te can effectively inhibit the dissolution of vanadium ions, thereby promoting the activity of VSe2 and improving the utilization of VSe2. Thus, the synergistic effect of the intercalation and conversion mechanisms endows the Te/VSe2 hybrid with excellent reversible capacity of 162 mA h g-1 under a current density of 0.1 A g-1 and a durable cycling ability (85% capacity retention after 1000 cycles at 0.8 A g-1). This work demonstrates the feasibility of the strategy by integrating intercalation- and conversion-type materials to develop outstanding cathode for AZIBs.