Nano-HxMoO3 cathodes with fast kinetics and long cycle stability via H+ pre-intercalation and nano-engineering for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) have gained significant attention due to their high safety profile and potential for cost-effectiveness. However, the lack of rapid kinetic and durable cycling cathode materials has impeded the development of AZIBs. The present study suggests the implementation of synthesizing nano-H _xMoO ₃ through a H ⁺-based intercalation strategy in nano α-MoO ₃ to effectively address these concerns. The electrochemical kinetics of H _xMoO ₃ exhibit significant improvement, as shown by data analyses of cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique. In addition, the results of the charge and discharge tests show that the H _xMoO ₃ cathode has significantly less capacity degradation during the first discharge than MoO ₃ and a more stable structure. As a result, the H _xMoO ₃ cathode demonstrated outstanding electrochemical performance, exhibiting discharge capacities of 215 and 158 mAh g ⁻¹ at current densities of 0.5 and 5 A g ⁻¹, as comparison the MoO ₃ cathode only have 189 and 142 mAh g ⁻¹. Moreover, the H _xMoO ₃ cathode maintained 74% of its initial capacity after 100 cycles at a current density of 0.5 A g ⁻¹. Even after 2000 cycles at a current density of 5 A g ⁻¹, H _xMoO ₃ maintains 44% of its original capacity, whereas MoO ₃ only retains 30%.