Enabling Ultrastable Alkali Metal Anodes by Artificial Solid Electrolyte Interphase Fluorination

• DOI: 10.1021/acs.nanolett.2c00616
• Publication Date: 2022-05-18T18:04:06Z
• Authors: Yifeng Cheng; Xuming Yang; Menghao Li; Xiangyan Li; Xinzhen Lu; Duojie Wu; Bing Han; Qing Zhang; Yuanmin Zhu; Meng Gu
• Keywords: Fluorides; Halogenation; Sodium; 02 engineering and technology; Lithium; 0210 nano-technology; Electrodes; Interphase; 7. Clean energy

The high specific capacity of alkalic metal (Li, Na, and K) anodes has drawn widespread interest; however, the practical applications of alkalic metal anodes have been hampered by dendrite growth and interfacial instability, resulting in performance deterioration and even safety issues. Here, we describe a simple method for building tunable fluoride-based artificial solid-electrolyte interphase (SEI) from the fluorination reaction of alkali metals with a mild organic fluorinating reagent. Comprehensive characterization by advanced electron microscopes shows that the LiF-based artificial SEI adopts a crystal-glass structure, which enables efficient Li ion transport and improves structural integrity against the volume changes that occur during Li plating/stripping. Compared with bare Li anode, the ones with artificial SEI exhibit decreased voltage hysteresis, enhanced rate capability, and prolonged cycle life. This method is also applied to generate fluoride-based artificial SEI on Na and K metal anodes that brings significant improvement in battery performance.