Surface modification using heptafluorobutyric acid to produce highly stable Li metal anodes

• Published in: Nature communications Vol. 14; no. 1; p. 2883
• Main Authors: Xie, Yuxiang, Huang, Yixin, Zhang, Yinggan, Wu, Tairui, Liu, Shishi, Sun, Miaolan, Lee, Bruce, Lin, Zhen, Chen, Hui, Dai, Peng, Huang, Zheng, Yang, Jian, Shi, Chenguang, Wu, Deyin, Huang, Ling, Hua, Yingjie, Wang, Chongtai, Sun, Shigang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19-05-2023; Nature Publishing Group; Nature Portfolio
• Subjects: 119/118; 132/124; 140/58; 147/135; 639/301/299/891; 639/4077/4079/891; 639/638/161/891; Acids; Anodes; Dendrites; Deposition; Electric bridges; Electrode materials; Electrolytes; Electrolytic cells; Humanities and Social Sciences; Ion flux; Lithium; Lithium ions; Metals; multidisciplinary; Organic acids; Science; Science (multidisciplinary); Specific capacity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-023-38724-x

The Li metal is an ideal anode material owing to its high theoretical specific capacity and low electrode potential. However, its high reactivity and dendritic growth in carbonate-based electrolytes limit its application. To address these issues, we propose a novel surface modification technique using heptafluorobutyric acid. In-situ spontaneous reaction between Li and the organic acid generates a lithiophilic interface of lithium heptafluorobutyrate for dendrite-free uniform Li deposition, which significantly improves the cycle stability (Li/Li symmetric cells >1200 h at 1.0 mA cm
−2
) and Coulombic efficiency (>99.3%) in conventional carbonate-based electrolytes. This lithiophilic interface also enables full batteries to achieve 83.2% capacity retention over 300 cycles under realistic testing condition. Lithium heptafluorobutyrate interface acts as an electrical bridge for uniform lithium-ion flux between Li anode and plating Li, which minimizes the occurrence of tortuous lithium dendrites and lowers interface impedance.
Development of lithium metal anodes is limited due to the dendritic growth and high reactivity of metal lithium. Here authors propose a surface modification strategy using heptafluorobutyric acid to form a lithiophilic interface, which enables uniform Li deposition and improving battery performance.