Lean electrolyte conditions are highly pursued for the practical lithium (Li) metal batteries. The previous studies on the Li metal anodes, in general, exhibited good stability with a large excess of electrolyte. However, the targeted design of Li hosts under relatively low electrolyte conditions has been rarely studied so far. Herein, we have shown that the electrolyte con-sumption severely affects the cycling stability of Li metal anode. Considering carbon hosts as typical examples, we innova-tively employed the in-situ synchrotron X-ray diffraction, in-situ Raman spectroscopy and theoretical computations to ob-tain better understanding of the Li nucleation/deposition processes. Besides, we showed the usefulness of in-situ electro-chemical impedance spectra to analyze interfacial fluctuation at the Li/electrolyte interface, and together with the nuclear magnetic resonance data to quantify electrolyte consumption. We have found that uneven Li nucleation/deposition and the crack of surface-area-derived solid-electrolyte-interface (SEI) layer both leads to a great consumption of electrolyte. Then, we suggested a design principle for Li host to overcome the electrolyte loss, that is, uneven growth of Li structure and the crack of SEI layer must be simultaneously controlled. As a proof of concept, we demonstrated the usefulness of a 3D low-surface-area defective graphene host (L-DG) to control Li nucleation/deposition and stabilize SEI layer, contributing to a highly reversible Li plating/stripping. As a result, such a Li host can achieve stable cycles (e.g., 1.0 mAh cm-2) with a low elec-trolyte loading (10 μL). This work demonstrates the necessity to design Li metal anodes under lean electrolyte conditions and brings the Li metal batteries a step closer to their practical applications.

中文翻译：

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原位光谱法揭示贫电解质锂金属阳极设计原理

对于实用的锂 (Li) 金属电池，人们高度追求贫电解质条件。先前对锂金属负极的研究通常在电解质过量时表现出良好的稳定性。然而，迄今为止，很少有人研究在相对低电解质条件下锂主体的目标设计。在这里，我们已经表明电解质消耗严重影响锂金属负极的循环稳定性。以碳主体为典型例子，我们创新地采用原位同步加速器X射线衍射、原位拉曼光谱和理论计算来更好地理解锂的成核/沉积过程。此外，我们展示了原位电化学阻抗谱在分析锂/电解质界面的界面波动方面的有用性，并与核磁共振数据一起量化电解质消耗。我们发现不均匀的锂成核/沉积和表面积衍生的固体电解质界面（SEI）层的裂纹都会导致电解质的大量消耗。然后，我们提出了克服电解质损失的锂主体设计原则，即必须同时控制锂结构的不均匀生长和SEI层的裂纹。作为概念证明，我们展示了 3D 低表面积缺陷石墨烯主体 (L-DG) 在控制锂成核/沉积和稳定 SEI 层方面的有用性，有助于高度可逆的锂电镀/剥离。因此，这种锂主体可以在低电解质负载（10 μL）的情况下实现稳定的循环（例如，1.0 mAh cm-2）。