Offense‐Defense‐Balanced Strategy Escorting Tellurium Oxidation Conversion towards Energetic and Long‐Life Zn Batteries

Abstract

AbstractAmong six‐electron Te conversion for energetic aqueous Zn batteries, the main capacity contributor, Te0/Te4+ redox usually causes substantial battery capacity/life discount due to its sluggish kinetics/poor reversibility. Herein, for the first time, an offense‐defense‐balanced strategy to simultaneously address the deficiencies is reported. Beyond previous proton‐ or reductant‐regulated solutions, this strategy efficaciously reconciles the pending capacity‐lifespan conflict. As a proof of concept, additive‐level nucleophilic chlorine ions (Cl−) and reductive glucose (Glu) in electrolytes are synergistically employed as “offensiver” and “defender” for Te0/Te4+ conversion, respectively. The Cl−/Glu co‐additive well inherits the nucleophilic motivation effect of Cl− on Te0/Te4+ conversion, and eliminates the formation of Cl−‐induced diffluent metastable phase (γ‐TeO2), enabling a deep and highly reversible Te0/Te4+ redox. Compared with co‐additive‐free electrolytes, the activation energy for Te conversion is lowered (61.4 vs. 52.8 kJ mol−1), and the shuttle of active materials is effectively inhibited. Consequently, Zn‖Te batteries deliver a volumetric capacity of approximately theoretical value (2409 mAh cm−3) at 0.2 A g−1, and a 15∼30‐fold longer lifespan than those in conventional electrolytes (over 5000 cycles with a decay of only 0.15‰ per cycle at 4 A g−1). This work opens a new avenue to develop other chalcogen conversion‐based aqueous Zn batteries.