Huang Dequan, Zeng Cuihong, Liu Menghao, Chen Xiaorong, Li Yahao, Zou Jinshuo, Pan Qichang, Zheng Fenghua, Wang Hongqiang, Li Qingyu, Hu Sijiang
Guangxi Key Laboratory of Low Carbon Energy Materials, Guangxi Scientific and Technological Achievements Transformation Pilot Research Base of Electrochemical Energy Materials and Devices, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, P. R. China.
School of Automobile Engineering, Guilin University of Aerospace Technology, Guilin, 541004, P. R. China.
Small. 2025 Mar;21(10):e2412259. doi: 10.1002/smll.202412259. Epub 2025 Jan 31.
Inhomogeneous lithium (Li) deposition and unstable solid electrolyte interphase are the main causes of short cycle life and safety issues in Li metal batteries (LMBs). Developing a 3D structured matrix current collector and novel electrolyte are feasible strategies to tackle these issues. Ether-based electrolytes are widely used in LMBs. However, a fundamental understanding of Li-ion coordination and solvent remains incomplete. Here, lithiophilic Ag-Cu mesh is designed as the current collector to boost rapid Li-ion flux and Li metal nucleation. Meanwhile, dimethoxyethane (DME)/dioxolane (DOL) are used as complex solvents to enable lower interfacial resistance. The solvation structures at the interfaces of different collectors with different electrolytes are investigated. By applying in operando Raman spectroscopy, it is demonstrated that bis(trifluoromethylsulfonyl)imide TFSIand DME molecules are highly coordinated with Li compared with DOL molecules. Furthermore, lithiophilic 3D Ag-Cu mesh tunes Li solvation/desolvation, resulting in a uniform deposition. The Ag-Cu mesh/Li symmetric cells demonstrate long-term cycling life up to 1200 h and Coulombic efficiency of 98.6% over 200 cycles at 1 mA cm. The Ag-Cu mesh/Li||LiNiCoMnO cells exhibit an initial discharge capacity of 208.7 mAh g at 1.0 C with a capacity retention of 76.1% after 500 cycles.
锂（Li）不均匀沉积和不稳定的固体电解质界面是锂金属电池（LMBs）循环寿命短和安全问题的主要原因。开发三维结构化基体集流体和新型电解质是解决这些问题的可行策略。醚基电解质在LMBs中被广泛使用。然而，对锂离子配位和溶剂的基本理解仍不完整。在此，设计亲锂性Ag-Cu网作为集流体，以提高锂离子通量和锂金属成核速度。同时，使用二甲氧基乙烷（DME）/二氧戊环（DOL）作为复合溶剂，以降低界面电阻。研究了不同集流体与不同电解质界面处的溶剂化结构。通过使用原位拉曼光谱，结果表明，与DOL分子相比，双（三氟甲基磺酰）亚胺TFSI和DME分子与Li的配位性更高。此外，亲锂性三维Ag-Cu网调节Li的溶剂化/去溶剂化过程，从而实现均匀沉积。Ag-Cu网/Li对称电池在1 mA cm下展示了长达1200 h的长期循环寿命以及超过200次循环的98.6%的库仑效率。Ag-Cu网/Li||LiNiCoMnO电池在1.0 C下的初始放电容量为208.7 mAh g，在500次循环后容量保持率为76.1%。
