Aqueous zinc-metal batteries are plagued by poor Zn reversibility owing to zinc dendrite and layered double hydroxide (LDH) formation. Here, we introduce a novel additive—N,N-dimethylformamidium trifluoromethanesulfonate (DOTf)—in a low-cost aqueous electrolyte that can very effectively address these issues. The initial water-assisted dissociation of DOTf into triflic superacid creates a robust nanostructured solid-electrolyte interface (SEI)—revealed by operando spectroscopy and cryomicroscopy—which excludes water and enables dense Zn deposition. We demonstrate excellent Zn plating/stripping in a Zn||Cu asymmetric cell for more than 3,500 cycles. Furthermore, near 100% CE is realized at a combined high current density of 4 mA cm⁻² and an areal capacity of 4 mAh cm⁻² over long-term cycling. Zn||Zn_0.25V₂O₅·nH₂O full cells retain ∼83% of their capacity after 1,000 cycles with mass-limited Zn anodes. By restricting the depth of discharge, the cathodes exhibit less proton intercalation and LDH formation with an extended lifetime of 2,000 cycles.

由于锌枝晶和层状双氢氧化物 (LDH) 的形成，水系锌金属电池受到锌可逆性差的困扰。在这里，我们在低成本的水性电解质中引入了一种新型添加剂 - N,N-二甲基甲酰胺三氟甲磺酸盐 (DOTf)，可以非常有效地解决这些问题。DOTf 最初的水辅助解离成三氟甲磺酸过酸产生了一个坚固的纳米结构固体电解质界面 (SEI)——通过操作光谱学和低温显微镜揭示——它排除了水并实现了致密的 Zn 沉积。我们在 Zn||Cu 非对称电池中展示了出色的 Zn 电镀/剥离超过 3,500 次循环。^{此外，在 4 mA cm -2的高电流密度和 4 mAh cm -2}的面积容量的组合下实现了接近 100% 的 CE长期骑自行车。Zn||Zn _0.25 V ₂ O ₅ ·nH ₂ O 全电池在使用质量受限的 Zn 阳极循环 1,000 次后仍能保持约 83% 的容量。通过限制放电深度，阴极表现出较少的质子嵌入和 LDH 形成，并延长了 2,000 次循环的寿命。