Nano-Hxmoo3 Cathodes with Fast Kinetics and Long Cycle Stability Via H+ Pre-Intercalation and Nano-Engineering for Aqueous Zinc-Ion Batteries

Abstract

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-HxMoO3 through a H+-based intercalation strategy in nano α-MoO3 to effectively address these concerns. The electrochemical kinetics of HxMoO3 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 HxMoO3 cathode has significantly less capacity degradation during the first discharge than MoO3 and a more stable structure. As a result, the HxMoO3 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 MoO3 cathode only have 189 and 142 mAh g-1. Moreover, the HxMoO3 cathode maintained 81% 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, HxMoO3 maintains 44% of its original capacity, whereas MoO3 only retains 30%.

Keywords: aqueous zinc-ion batteries, molybdenum oxide, H+-based intercalation, Cathode, electrochemical kinetics