Trehalose in Trace Quantities as a Multifunctional Electrolyte Additive for Highly Reversible Zinc Metal Anodes

The unsatisfactory performance of Zn metal anodes significantly impedes the commercial application of aqueous zinc-ion batteries (AZIBs). Herein, we introduce a trace amount of a multifunctional trehalose additive to enhance the stability and reversibility of Zn metal anodes. The trehalose additive exhibits a stronger Zn²⁺ ion affinity due to abundant lone-pair electrons, disrupting hydrogen bonds in H₂O, regulating solvation structures, and tuning the Zn–electrolyte interface. Consequently, the Zn metal anode demonstrates a remarkable Coulombic efficiency of 99.80% and a cycle stability exceeding 4500 h at 1 mA cm^–2. Even under stringent conditions of 10 mA cm^–2, the Zn metal anode maintains a cumulative capacity of 2500 mA h cm^–2 without a short circuit. Furthermore, Zn//Zn symmetric batteries exhibit excellent low-temperature cycle performance (over 400 h at −10 °C). As a proof of concept, assembled Zn//NH₄V₄O₁₀ and Zn//MnO₂ pouch cells demonstrate an improved electrochemical performance. This work presents an electrolyte additive strategy for achieving stable zinc anode operation in AZIBs.