Magnesium (Mg) anodes typically experience electrochemical passivation and dendrite formation with conventional electrolytes during cell storage and operation, which results in a rapid decline in cyclability and shortened lifespans. These concerns supposedly relate to the features of the Mg/electrolyte interface. Herein, we report that Mg(BH₄)₂-rich artificial hybrid interphase (AHI) fabricated on Mg by a simple cation replacement method effectively ensures electrochemical activity and nondendritic interface. This can be attributed to the synergy of fast Mg²⁺ transfer, high electronically insulating and structural stability, etc., of AHI, as revealed by experimental and computational findings. The symmetric cell presents a low-voltage polarization of 230 mV and prolonged cycling life of over 1300 h at 1 mA cm^–2 in 0.5 M Mg[bis(trifluoromethanesulfonyl)imide (TFSI)]₂/dimethoxyethane (DME) electrolyte. Meanwhile, the full cells paired with a Mo₆S₈ cathode at various rates with desirable stability are also achieved. Our work provides further insight into the design of a versatile non-MgCl₂ artificial layer specialized for rechargeable Mg batteries.

中文翻译：

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基于硼氢化物的中间相可在传统电解质中实现可逆镁金属阳极

在电池储存和运行过程中，镁 (Mg) 阳极通常会经历电化学钝化，并与传统电解质形成枝晶，从而导致循环性能迅速下降并缩短使用寿命。据推测，这些问题与镁/电解质界面的特征有关。在此，我们报道了通过简单的阳离子置换方法在Mg上制备的富含Mg(BH ₄ ) ₂的人工杂化中间相(AHI)，有效地确保了电化学活性和非枝晶界面。实验和计算结果表明，这可以归因于AHI的快速Mg ²⁺转移、高电子绝缘和结构稳定性等的协同作用。该对称电池在 0.5 M Mg[双(三氟甲磺酰)亚胺 (TFSI)] _{2 /二甲氧基乙烷 (DME) 电解质中，在 1 mA cm} ^–2下具有 230 mV 的低电压极化和超过 1300 小时的延长循环寿命。同时，还实现了以各种速率与Mo ₆ S ₈阴极配对的全电池，并具有理想的稳定性。我们的工作为专门用于可充电镁电池的多功能非 MgCl ₂人造层的设计提供了进一步的见解。