Single‐Solvent‐Based Electrolyte Enabling a High‐Voltage Lithium‐Metal Battery with Long Cycle Life
Single‐Solvent‐Based Electrolyte Enabling a High‐Voltage Lithium‐Metal Battery with Long Cycle Life
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DOI：
10.1002/aenm.202300918
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发表时间：
2023-06
影响因子：
27.8
通讯作者：
Yuanqin Li;Mingzhu Liu;K. Wang;C. Li;Ying Lu;Aditya Choudhary;Taylor Ottley;D. Bedrov;L. Xing;Weishang Li
中科院分区：
文献类型：
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作者：
Yuanqin Li;Mingzhu Liu;K. Wang;C. Li;Ying Lu;Aditya Choudhary;Taylor Ottley;D. Bedrov;L. Xing;Weishang Li
锂金属阳极（LMA）的应用可以显著提高最先进锂离子电池的能量密度。已经开发了许多新的电解质体系以形成稳定的固体电解质界面（SEI）膜，从而实现LMA的长期循环稳定性。不幸的是，这些电解质面临的共同问题是氧化稳定性差，很少支持高压锂金属电池（LMB）的循环。在这项工作中，提出了一种新的单组分溶剂二甲氧基（甲基）（3，3，3-三氟丙基）硅烷。由该溶剂和3 μ m LiFSI盐组成的电解质成功支持有限锂（50 μm）的长期循环稳定性||实验和理论研究结果表明，该电解质在高压LMB中的优异性能主要归因于其独特的溶剂化结构及其在LMA和高压阴极表面构建高度稳定和坚固的界面相的能力。有趣的是，这种电解质系统通过提高FSI-的双电子还原活性，在LMA表面构建了富含LiF和Li 3 N的稳定SEI膜，而不添加用于LMB的众所周知的添加剂LiNO 3。所提出的电解质的设计思想可以指导高压LMB的开发。
The application of Li‐metal‐anodes (LMA) can significantly improve the energy density of state‐of‐the‐art lithium ion batteries. Lots of new electrolyte systems have been developed to form a stable solid electrolyte interphase (SEI) films, thereby achieving long‐term cycle stability of LMA. Unfortunately, the common problem faced by these electrolytes is poor oxidation stability, which rarely supports the cycling of high‐voltage Li‐metal batteries (LMBs). In this work, a new single‐component solvent dimethoxy(methyl)(3,3,3‐trifluoropropyl) silane is proposed. The electrolyte composed of this solvent and 3 m LiFSI salt successfully supports the long‐term cycle stability of limited‐Li (50 µm)||high loading LiCoO2 (≈20 mg cm−2) cell at 4.6 V. Experiments and theoretical research results show that the outstanding performance of the electrolyte in high‐voltage LMBs is mainly attributed to its unique solvation structures and its great ability to build a highly stable and robust interphase on the surface of LMA and high‐voltage cathodes. Interestingly, this proposed electrolyte system builds a stable SEI film rich in LiF and Li3N on the surface of LMA by improving the two‐electron reduction activity of FSI− without adding LiNO3, the well‐known additive used for LMBs. The design idea of the proposed electrolyte can guide the development of high‐voltage LMBs.