Electrolyte Engineering via Competitive Solvation Structures for Developing Longevous Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) are troubled by the severe Zn dendrite growth and side reactions, manifesting as low coulombic efficiency and poor cyclic stability. Electrolyte engineering is regarded as an efficient method to improve Zn metal reversibility. Herein, a distinctive electrolyte regulation strategy is demonstrated for long-lasting ZIBs through the construction of competitive solvation structures. In the composite aqueous system, the insoluble LiNO3 in dimethyl carbonate (DMC) is introduced to outwit active water dissociation from Zn2+ coordination environment, and the organic/anion-enriched solvation structure enables the formation of a stable interface to effectively restrain adverse reactions. Distinctly, the Zn metal anode exhibits inhibited dendrite growth with high reversibility of plating/stripping processes over 1600 h with an exceptional cumulative capacity over 16 Ah cm-2, an ultra-long lifespan over high-temperature (50 degrees C), and high discharge of depth (65%). Furthermore, the Zn || V2O5 full battery can operate stably over 1000 cycles at 1 A g-1. This work points a direction to effectively solve the major challenges of ZIBs through the collaborative construction of a regulated electrolyte environment and interfacial chemistry. A competitive solvation structure strategy is proposed to further immobilize free water molecules and construct an organic/anion-derived solid electrolyte interphase for dendrite-free and long lifespan zinc ion batteries, providing an emerging strategy toward practical energy storage systems.image