Metallic zinc is an ideal anode due to its high theoretical capacity (820 mAh g⁻¹), low redox potential (−0.762 V versus the standard hydrogen electrode), high abundance and low toxicity. When used in aqueous electrolyte, it also brings intrinsic safety, but suffers from severe irreversibility. This is best exemplified by low coulombic efficiency, dendrite growth and water consumption. This is thought to be due to severe hydrogen evolution during zinc plating and stripping, hitherto making the in-situ formation of a solid–electrolyte interphase (SEI) impossible. Here, we report an aqueous zinc battery in which a dilute and acidic aqueous electrolyte with an alkylammonium salt additive assists the formation of a robust, Zn²⁺-conducting and waterproof SEI. The presence of this SEI enables excellent performance: dendrite-free zinc plating/stripping at 99.9% coulombic efficiency in a Ti||Zn asymmetric cell for 1,000 cycles; steady charge–discharge in a Zn||Zn symmetric cell for 6,000 cycles (6,000 h); and high energy densities (136 Wh kg⁻¹ in a Zn||VOPO₄ full battery with 88.7% retention for >6,000 cycles, 325 Wh kg⁻¹ in a Zn||O₂ full battery for >300 cycles and 218 Wh kg⁻¹ in a Zn||MnO₂ full battery with 88.5% retention for 1,000 cycles) using limited zinc. The SEI-forming electrolyte also allows the reversible operation of an anode-free pouch cell of Ti||Zn_xVOPO₄ at 100% depth of discharge for 100 cycles, thus establishing aqueous zinc batteries as viable cell systems for practical applications.

金属锌是理想的阳极，因为它具有高理论容量（820 mAh g ^-1）、低氧化还原电位（-0.762 V 与标准氢电极相比）、高丰度和低毒性。当用于水系电解质时，它也带来了本质安全性，但存在严重的不可逆性。库仑效率低、枝晶生长和耗水量低就是最好的例证。这被认为是由于在镀锌和剥离过程中严重的氢析出，迄今为止无法原位形成固体电解质界面（SEI）。在这里，我们报告了一种水性锌电池，其中含有烷基铵盐添加剂的稀酸性水性电解质有助于形成坚固的 Zn ²⁺- 导电和防水的 SEI。这种 SEI 的存在可实现出色的性能：在 Ti||Zn 不对称电池中以 99.9% 的库仑效率进行 1,000 次循环的无枝晶镀锌/剥离；在 Zn||Zn 对称电池中进行 6,000 次循环（6,000 小时）的稳定充放电；和高能量密度（在 Zn||VOPO _{4完整电池中为 136 Wh kg} ^-1 ，在>6,000 次循环中保持 88.7%，在 Zn||O _{2完整电池中为 325 Wh kg} ^-1 ，在>300 次循环中和 218 Wh kg ^-1在 Zn||MnO ₂完整电池中，在 1,000 次循环中保持 88.5%），使用有限的锌。_{形成 SEI 的电解质还允许 Ti||Zn x} VOPO ₄的无阳极软包电池的可逆操作在 100% 的放电深度下进行 100 次循环，从而将水性锌电池确立为实际应用的可行电池系统。