High‐Entropy Electrolytes with High Disordered Solvation Structures for Ultra‐Stable Zinc Metal Anodes

Abstract

Aqueous zinc‐ion batteries (ZIBs) are playing an increasingly important role in the field of energy storage. However, their practical applications are handicapped by severe dendrite formation and side reactions on zinc anodes. Herein, a low‐concentration high‐entropy (HE) electrolyte strategy is proposed to achieve high reversibility and ultra‐durable zinc metal anode. Specifically, this HE electrolyte features multiple anions participating in coordination and highly disordered solvation shells, which would disrupt intrinsic H‐bond network between water molecules and suppress interfacial side reactions. Moreover, these diversified weakly solvated structures can lower solvation energy of Zn2+ solvation configurations and enhance zinc ion diffusion kinetics, promoting uniform Zn deposition and electrode interface stability. Consequently, Zn||Zn symmetric cells exhibit over 2,000 hours of cycling stability, and Zn||Cu asymmetric cells achieve high average Coulombic efficiency of 99.9% over 500 cycles. Furthermore, the Zn||PANI full cell with optimized HE‐50mM electrolyte delivers a high specific capacity of 110.7 mAh g‐1 over 2,000 cycles at 0.5 A g‐1 and a capacity retention of 70.4% at 15 A g‐1 after 10,000 cycles. Remarkably, even at a low temperature of ‐20 °C, the Zn||PANI full cells equipped with HE‐50mM electrolyte still demonstrate long‐term cycling stability over 600 cycles with high‐capacity retention of 93.5%.