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

• DOI: 10.1021/jacs.0c12051
• Publication Date: 2021-02-15T23:16:54Z
• Authors: Yingli Wang; Fangming Liu; Guilan Fan; Xiaoguang Qiu; Jiuding Liu; Zhenhua Yan; Kai Zhang; Fangyi Cheng; Jun Chen
• Keywords: Pharmacology; Chemical Sciences not elsewhere classified; Physiology; Biophysics; Plant Biology; SEI-protected Li anode; Cell Biology; Li x PO y F z; lithium anode; Biochemistry; 7. Clean energy; 01 natural sciences; 0104 chemical sciences; Robust Lithium Anodes Engineering; LiFePO 4 cathode; electroless electrolyte-soaking app.; Developmental Biology; Biological Sciences not elsewhere classified

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, LixPOyFz, 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.