The nature of dendrite-free magnesium (Mg) metal anodes is an important advantage in rechargeable magnesium batteries (RMBs). However, this traditional cognition needs to be reconsidered due to inhomogeneous Mg deposits under extreme electrochemical conditions. Herein, we report a three-dimensional (3D) Cu-based host with magnesiophilic Ag sites (denoted as “Ag@3D Cu mesh”) to regulate Mg deposition behaviors and achieve uniform Mg electrodeposition. Mg deposition/stripping behaviors are obviously improved under the cooperative effect of nanowire structures and Ag sites. The test results indicate that nucleation overpotentials are reduced distinctly and cycling performances are prolonged, suggesting that the general rules of 3D structures and affinity sites improve the durability and reversibility of Mg deposition/stripping. Besides, a unique concave surface structure can induce Mg to deposit into the interior of the interspace, which utilizes Mg more efficiently and leads to improved electrochemical performances with limited Mg content. Furthermore, in situ optical microscopic images show that the Ag@3D Cu mesh can attain a smooth surface, nearly without Mg protrusions, under 8.0 mA cm^–2, which prevents premature short circuits. This report is a pioneering work to demonstrate the feasibility of modification of Cu-based current collectors and the necessity of functional current collectors to improve the possibility of practical applications for RMBs.

中文翻译：

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用纳米线和亲镁银位点修饰铜网以诱导均匀的镁沉积

无枝晶镁 (Mg) 金属阳极的性质是可充电镁电池 (RMB) 的重要优势。然而，由于极端电化学条件下的不均匀镁沉积物，这种传统认知需要重新考虑。在此，我们报告了一种具有亲镁 Ag 位点（表示为“Ag@3D Cu 网”）的三维（3D）Cu 基主体，以调节 Mg 沉积行为并实现均匀的 Mg 电沉积。在纳米线结构和Ag位点的协同作用下，Mg沉积/剥离行为明显改善。测试结果表明，成核过电位明显降低，循环性能延长，表明 3D 结构和亲和位点的一般规则提高了 Mg 沉积/剥离的耐久性和可逆性。除了，独特的凹面结构可以诱导镁沉积到间隙内部，从而更有效地利用镁，并在有限的镁含量下提高电化学性能。此外，原位光学显微图像显示，Ag@3D Cu 网格可以在 8.0 mA cm 下获得光滑的表面，几乎没有 Mg 突起。^–2，可防止过早短路。该报告是一项开创性工作，证明了铜基集流体改性的可行性以及功能集流体提高人民币实际应用可能性的必要性。