High voltage and robust lithium metal battery enabled by highly-fluorinated interphases

The growth of dendrites and the parasitic reactions on Li metal anodes plague the practical applications of Li metal batteries (LMBs). Herein, we report a novel all-fluorinated electrolyte, named as FFH, for LMBs. The FFH all-fluorinated electrolyte can form a robust and stable LiF-enriched interphase for ameliorating the dendrite growth and realizing high-voltage operations. The assembled battery has achieved a high cycling stability for more than 1000 h with a desirable Coulombic efficiency of 97.1% for Li-metal plating/stripping. Furthermore, the FFH all-fluorinated electrolyte is highly compatible with Ni-rich cathodes, including NCM811 (Li[Ni0.8Co0.1Mn0.1]O2) and Ni92 (Li[Ni0.92Co0.04Mn0.04]O2), as evidenced by a CE of ∼99.8% for the Li||NCM811 cell and 99.9% for the Li||Ni92 cell (4.5 V). In addition, the Li||Ni92 cell with the FFH all-fluorinated electrolyte shows a surprising cycling stability (68% capacity retention at the 500th cycle) and high Coulombic efficiency (∼99.8% after 500 cycles) at 1 C under 5 V. The FFH electrolyte developed in this work provides an effective strategy for the safe operation of high-performance LMBs.