Very Stable Lithium Metal Stripping-Plating at a High Rate and High Areal Capacity in Fluoroethylene Carbonate-Based Organic Electrolyte Solution

We report the highly stable galvanostatic cycling of lithium metal (Li) electrodes in a symmetrical Lilelectrolyte solution! Li coin-cell configuration at a high rate and high areal capacity using fluoroethylene carbonate (FEC)-based electrolyte solutions [1 M LiPF6 in FEC/dimethyl carbonate (DMC)]. The FEC-based electrolyte solution shows cycling behavior that is markedly better than that observed for the cells cycled with an ethylene carbonate (EC)-based electrolyte solution (1 M LiPF6 in EC/DMC). With FEC-based electrolyte solution, LilLi cells can be cycled at 2 mA cm(-2) with an areal capacity of 3.3 mAh cm(-2) for more than 1100 cycles, and full Lil LiNi0.6Co0.2Mn0.2O2 (NMC) cells with high areal loading cathode demonstrate stable cycling with the same capacity during 90 cycles. An increase in areal capacity up to 6 mA h cm(-2) does not affect the shape of the voltage profile of the symmetric LilLi cells. The reason for this high performance is the formation of a stable and efficient solid electrolyte interphase (SEI) on the surface of the Li metal electrodes cycled in the FEC-based solution. The composition of the SEI is analyzed by Fourier transform infrared spectroscopy.