Increasing demands for advanced lithium batteries with higher energy density have resurrected the use of lithium metal as an anode, whose practical implementation has still been restricted, because of its intrinsic problems originating from the high reactivity of elemental lithium metal. Herein, we explore a facile strategy of doping gas phase into electrolyte to stabilize lithium metal and suppress the selective lithium growth through the formation of stable and homogeneous solid electrolyte interphase (SEI) layer. We find that the sulfur dioxide gas additive doped in electrolyte significantly improves both chemical and electrochemical stability of lithium metal electrodes. It is demonstrated that the cycle stability of the lithium cells can be remarkably prolonged, because of the compact and homogeneous SEI layers consisting of Li–S–O reduction products formed on the lithium metal surface. Simulations on the lithium metal growth process suggested the homogeneity of the protective layer induced by the gas-phase doping is attributable for the effective prevention of the selective growth of lithium metal. This study introduces a new simple approach to stabilize the lithium metal electrode with gas-phase doping, where the SEI layer can be rationally tunable by the composition of gas phase.

中文翻译：

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简单有效的气相掺杂保护锂金属电池中的锂金属

对具有更高能量密度的高级锂电池的需求的增加已经使锂金属作为阳极的使用被复活，由于其固有的问题源于元素锂金属的高反应性，其实际实施仍然受到限制。本文中，我们探索了一种将气相掺杂到电解质中以稳定锂金属并通过形成稳定且均匀的固体电解质中间相（SEI）层来抑制选择性锂生长的简便策略。我们发现，掺杂在电解质中的二氧化硫气体添加剂可显着提高锂金属电极的化学和电化学稳定性。结果表明，锂电池的循环稳定性可以显着延长，由于在锂金属表面上形成了由Li–S–O还原产物组成的致密且均匀的SEI层。对锂金属生长过程的模拟表明，气相掺杂引起的保护层的均匀性可归因于有效防止锂金属的选择性生长。这项研究介绍了一种新的简单方法，可通过气相掺杂来稳定锂金属电极，其中SEI层可通过气相组成合理地调整。