Boosting the performance of aqueous zinc-ion battery by regulating the electrolyte solvation structure

Abstract

The practical implementation of aqueous Zn-ion batteries (ZIBs) for large-scale energy storage is impeded by the challenges of water-induced parasitic reactions and uncontrolled dendrite growth. Herein, we propose a strategy to regulate both anions and cations of electrolyte solvation structures to address above challenges, by introducing an electrolyte additive of 3-hydroxy-4-(trimethylammonio)butyrate (HTMAB) into ZnSO₄ electrolyte. Consequently, the deposition of Zn is significantly improved leading to a highly reversible Zn anode with paralleled texture. The Zn/Zn cells with ZnSO₄/HTMAB exhibit outstanding cycling performance, showcasing a lifespan exceeding 7500 h and an exceptionally high accumulative capacity of 16.47 Ah cm⁻². Zn/NaV₃O₈·1.5H₂O full cell displays a specific capacity of ~130 mAh g⁻¹ at 5 A g⁻¹ maintaining a capacity retention of 93% after 2000 cycles. This work highlights the regulation on both cations and anions of electrolyte solvation structures in optimizing interfacial stability during Zn plating/stripping for high performance ZIBs.