In-situ formation of LiF-rich solid-electrolyte interphases on 3D lithiophilic skeleton for stable lithium metal anode

Lithium (Li) metal with high theoretical capacity is considered as one of the important anode materials for the next-generation high-energy density batteries. However, the further commercial application of Li metal anode is hindered by the severe growth of uncontrollable Li dendrites and the destructive regrowth of unstable solid-electrolyte interphases (SEI) layer. Herein, through the combination of thin film deposition coating and in-situ fluoridation, a composite layer with the lithophilic layer and the LiF-rich SEI layer is realized on Cu foam current collector. Specifically, the lithiophilic layer on the surface of current collector helps to regulate the homogeneous Li plating/stripping behavior. More importantly, after in-situ fluoridation, the LiF-rich layer as a robustly artificial SEI can be in-situ generated on the surface of current collector during initial activation process to stabilize cycling performance with dendrite-free. Consequently, the well-designed 3D current collector enables dendrite-free Li deposition behavior, high average coulombic efficiency (97.74% for 500 cycles at 1 mA cm−2 & 1 mAh cm−2), stable Li plating/stripping behavior (over 2400 h with an ultra-low overpotential of 10 mV at 2 mA cm−2 & 2 mAh cm−2) and remarkable cycling stability/rate performance in both coin-type and pouch full cells. These encouraging results provide new insights into the design of high-performance Li metal anodes for the development of Li metal batteries.