High‐Capacity Zinc Anode with 96 % Utilization Rate Enabled by Solvation Structure Design

Abstract

Aqueous zinc‐ion batteries (AZBs) show promises for large‐scale energy storage. However, the zinc utilization rate (ZUR) is generally low due to side reactions in the aqueous electrolyte caused by the active water molecules. Here, we design a novel solvation structure in the electrolyte by introduction of sulfolane (SL). Theoretical calculations, molecular dynamics simulations and experimental tests show that SL remodels the primary solvation shell of Zn ²⁺, which significantly reduces the side reactions of Zn anode and achieves high ZUR under large capacities. Specifically, the symmetric and asymmetric cells could achieve a maximum of ∼96 % ZUR at an areal capacity of 24 mAh cm ⁻². In a ZUR of ∼67 %, the developed Zn−V ₂O ₅ full cell can be stably cycled for 500 cycles with an energy density of 180 Wh kg ⁻¹ and Zn‐AC capacitor is stable for 5000 cycles. This electrolyte structural engineering strategy provides new insight into achieving high ZUR of Zn anodes for high performance AZBs.