Boosting the Charge Storage Capability of Bi ₂ TeO ₅ Cathode Using Iodide Ions in Aqueous Zinc‐Based Batteries System

Abstract As insertion‐type cathode materials of aqueous Zn‐based batteries (ABs), bismuth chalcogenides/oxychalcogenides exhibits relatively limited capacities in ZnSO ₄ baseline electrolyte. This work finds that Bi ₂ TeO ₅ (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 .