Rechargeable Zn batteries hold great promise for large-scale energy storage applications but their reversibility is limited by non-compact and dendritic Zn deposition along with interfacial parasitic reactions in conventional electrolytes. Herein, we report an intrinsically safe, dilute, and hydrous organic electrolyte by coupling hydrated Zn(BF₄)₂ salt with trimethyl phosphate (TMP) solvent for highly reversible Zn batteries, without the need of concentrated electrolyte strategies. The formulated 1 m Zn(BF₄)₂/TMP enables spatially compact, dendrite-free, and corrosion-free Zn electrodeposition even at high areal capacity (5 and 10 mAh cm⁻²) using a pressure-free electrolytic cell. Moreover, the hydrous organic electrolyte with low water activity expands the electrochemical window to 3 V (versus Zn²⁺/Zn) and in-situ forms a protective ZnF₂-Zn₃(PO₄)₂-rich interphase on Zn. The resultant Zn electrode achieves long-term cycling over 4200 h with a superhigh cumulative plating capacity of 10500 mAh cm⁻² under 5 mA cm⁻² in Zn//Zn cell and exhibits high efficiency of 99.5% over 600 cycles in Zn//Cu cell (1 mA cm⁻²; 1 mAh cm⁻²). Moreover, this electrolyte supports the stable operation of a full Zn//V₂O₅·nH₂O battery by significantly suppressing cathode dissolution. This work would enlighten the design of hydrous organic electrolytes for practical Zn batteries.

可充电锌电池在大规模储能应用中具有很大的前景，但它们的可逆性受到非致密和树枝状锌沉积以及传统电解质中的界面寄生反应的限制。在此，我们报告了一种本质安全、稀释和含水的有机电解质，通过将水合 Zn(BF ₄ ) ₂盐与磷酸三甲酯 (TMP) 溶剂偶联，用于高度可逆的锌电池，无需浓缩电解质策略。配制的 1 m Zn(BF ₄ ) ₂ /TMP 即使在高面积容量（5 和 10 mAh cm ^-2) 使用无压电解池。此外，具有低水活度的含水有机电解质将电化学窗口扩大到3 V（相对于Zn ²⁺ /Zn），并在Zn上原位形成保护性富ZnF ₂ -Zn ₃ (PO ₄ ) ₂界面。所得的锌电极在 Zn//Zn 电池中实现了超过 4200 小时的长期循环，在 5 mA cm -2 下^{具有10500 mAh cm -2}的超高累积电镀容量，并且在 Zn//Zn 电池中在 600 次循环中表现出 99.5% 的高效率//铜电池（1 mA cm ^-2；1 mAh cm ^-2）。此外，该电解质支持全Zn//V _{2的稳定运行}O ₅ ·nH ₂ O 电池通过显着抑制正极溶解。这项工作将为实际锌电池的含水有机电解质的设计提供启示。