Electroless Formation of a Fluorinated Li/Na Hybrid Interphase for Robust Lithium Anodes

• Published in: Journal of the American Chemical Society 2021-02, Vol.143 (7), p.2829-2837
• Main Authors: Wang, Yingli, Liu, Fangming, Fan, Guilan, Qiu, Xiaoguang, Liu, Jiuding, Yan, Zhenhua, Zhang, Kai, Cheng, Fangyi, Chen, Jun
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.0c12051

Engineering a stable solid electrolyte interphase (SEI) is one of the critical maneuvers in improving the performance of a lithium anode for high-energy-density rechargeable lithium batteries. Herein, we build a fluorinated lithium/sodium hybrid interphase via a facile electroless electrolyte-soaking approach to stabilize the repeated plating/stripping of lithium metal. Jointed experimental and computational characterizations reveal that the fluorinated hybrid SEI mainly consisting of NaF, LiF, Li x PO y F z , and organic components features a mosaic polycrystalline structure with enriched grain boundaries and superior interfacial properties toward Li. This LiF/NaF hybrid SEI exhibits improved ionic conductivity and mechanical strength in comparison to the SEI without NaF. Remarkably, the fluorinated hybrid SEI enables an extended dendrite-free cycling of metallic Li over 1300 h at a high areal capacity of 10 mAh cm–2 in symmetrical cells. Furthermore, full cells based on the LiFePO4 cathode and hybrid SEI-protected Li anode sustain long-term stability and good capacity retention (96.70% after 200 cycles) at 0.5 C. This work could provide a new avenue for designing robust multifunctional SEI to upgrade the metallic lithium anode.