The electrochemical extraction of reactive metals, such as Li, Mg, Al, Ti, and rare-earth metals, from different electrolyte systems at low temperatures has been a longstanding challenge in the field of electrochemical extractive metallurgy. Water is an excellent green solvent; therefore, the electrodeposition of aqueous solutions of reactive metals would be more sustainable than traditional approaches involving molten salts and organic solvents. Inspired by the successful application of water-in-salt electrolytes for battery chemistry, we attempted the electrochemical extraction of metallic Li from water via its deposition on different substrates. We found that Li can be electrodeposited in the form of Li-based alloys and hydroxides, as identified by X-ray diffraction and X-ray photoelectron spectroscopy analysis, under certain conditions, and the mechanisms behind the observed electrochemical behaviour are discussed using different characterisation techniques and density functional theory calculations. In addition, the prospects for the electrodeposition of reactive metals from aqueous solutions are considered, and suggestions for further study are made. Thus, this work provides important insights regarding the electrochemical extraction of reactive metals from water at room temperature, and we believe that this work forms a basis for the development of safer batteries, as well as advanced electrodeposition and electrometallurgy technology.

在低温下从不同的电解质体系中电化学提取锂、镁、铝、钛和稀土金属等活性金属一直是电化学提取冶金领域的长期挑战。水是一种极好的绿色溶剂；因此，活性金属水溶液的电沉积比涉及熔盐和有机溶剂的传统方法更具可持续性。受到盐包水电解质在电池化学中的成功应用的启发，我们尝试通过在不同基材上的沉积从水中电化学提取金属锂。我们发现，通过 X 射线衍射和 X 射线光电子能谱分析，在一定条件下，锂可以以锂基合金和氢氧化物的形式电沉积，并且使用不同的表征技术和密度泛函理论计算讨论了所观察到的电化学行为背后的机制。此外，还考虑了从水溶液中电沉积活性金属的前景，并提出了进一步研究的建议。因此，这项工作提供了关于室温下从水中电化学提取活性金属的重要见解，我们相信这项工作为开发更安全的电池以及先进的电沉积和电冶金技术奠定了基础。考虑了从水溶液中电沉积活性金属的前景，并提出了进一步研究的建议。因此，这项工作提供了关于室温下从水中电化学提取活性金属的重要见解，我们相信这项工作为开发更安全的电池以及先进的电沉积和电冶金技术奠定了基础。考虑了从水溶液中电沉积活性金属的前景，并提出了进一步研究的建议。因此，这项工作提供了关于室温下从水中电化学提取活性金属的重要见解，我们相信这项工作为开发更安全的电池以及先进的电沉积和电冶金技术奠定了基础。