Boosting the Charge Storage Capability of Bi₂TeO₅ Cathode Using Iodide Ions in Aqueous Zinc-Based Batteries System

As insertion-type cathode materials of aqueous Zn-based batteries (ABs), bismuth chalcogenides/oxychalcogenides exhibits relatively limited capacities in ZnSO₄ baseline electrolyte. This work finds that Bi₂TeO₅ (BTO) cathode with pre-added I^- electrolyte additive can simultaneously achieve conversion and insertion chemistries, which enables aqueous BTO-Zn batteries to deliver an extraordinary electrochemical performance. As shown in the experiment results, the BTO cathode showcases an ultrahigh specific capacity of 534.9 mA h g^-1 at 0.5 A g^-1, excellent rate capability (237.3 mA h g^-1 at 10 A g^-1). In the estimation of cyclic durability, the capacity of the BTO cathode decreases from 271.2 to 171.1 mA h g^-1 during 2000 cycles at 10 A g^-1.