美国斯坦福大学Bao Zhenan研究团队报道了锂金属电位下双（氟磺酰基）亚胺衍生固体-电解质间相的电化学形成。相关研究成果发表在2024年12月2日出版的《自然—化学》。

锂双（氟磺酰基）酰亚胺基液体电解质有望在下一代锂金属电池中，实现高库仑效率和长循环寿命。然而，阴离子在固体电解质界面形成中的作用尚不清楚。

该文中，研究人员结合了电化学分析和X射线光电子能谱测量，包括样品洗涤和不洗涤，以及计算模拟，提出了电解质分解的反应途径，并将界面组分的溶解度与钝化效果联系起来。

研究发现，并非所有来自界面形成反应的产物都被掺入所得钝化层中，其中很大一部分存在于液体电解质中。研究还发现，通过引入更多的阴离子分解产物，高性能电解质可以在最小化电解质分解的情况下提供足够的钝化界面。

总体而言，该项工作提出了一种将电化学和表面分析相结合的系统方法，以全面描绘固体-电解质界面形成的过程，同时确定高性能电解质的关键属性，以指导未来的设计。

附：英文原文

Title: Electrochemical formation of bis(fluorosulfonyl)imide-derived solid-electrolyte interphase at Li-metal potential

Author: Yu, Weilai, Lin, Kuan-Yu, Boyle, David T., Tang, Michael T., Cui, Yi, Chen, Yuelang, Yu, Zhiao, Xu, Rong, Lin, Yangju, Feng, Guangxia, Huang, Zhuojun, Michalek, Lukas, Li, Weiyu, Harris, Stephen J., Jiang, Jyh-Chiang, Abild-Pedersen, Frank, Qin, Jian, Cui, Yi, Bao, Zhenan

Issue&Volume: 2024-12-02

Abstract: Lithium bis(fluorosulfonyl)imide-based liquid electrolytes are promising for realizing high coulombic efficiency and long cycle life in next-generation Li-metal batteries. However, the role of anions in the formation of the solid–electrolyte interphase remains unclear. Here we combine electrochemical analyses and X-ray photoelectron spectroscopy measurements, both with and without sample washing, together with computational simulations, to propose the reaction pathways of electrolyte decomposition and correlate the interphase component solubility with the efficacy of passivation. We discover that not all the products derived from interphase-forming reactions are incorporated into the resulting passivation layer, with a notable portion present in the liquid electrolyte. We also find that the high-performance electrolytes can afford a sufficiently passivating interphase with minimized electrolyte decomposition, by incorporating more anion-decomposition products. Overall, this work presents a systematic approach of coupling electrochemical and surface analyses to paint a comprehensive picture of solid–electrolyte interphase formation, while identifying the key attributes of high-performance electrolytes to guide future designs.

DOI: 10.1038/s41557-024-01689-5

Source: https://www.nature.com/articles/s41557-024-01689-5