© 2020 Elsevier B.V. Development of high energy density lithium metal batteries (LMBs) with high cycling stability is becoming more and more important. In this study, a novel and reliable electrolyte additive, 2-Fluoropyridine (2-FP), was successfully applied to enhance the stability of different commercial liquid electrolytes and effectively improve the performance of LMBs for the first time. The 2-FP additive was found to play a critical role in the decrease of Li nucleation as well as deposition overpotential, and finally supressing the Li-dendrites. As a result, the high-voltage LiNi1/3Mn1/3Co1/3O2 cathode (1.5 mAh cm−2)|Li metal cell using the commercial carbonate-based LiPF6 electrolyte with 2% of 2-FP additive exhibited a stable capacity retention of 67.6% even after 300-cycle test with a coulombic efficiency as high as 99.89% at 0.75 mA cm−2. Meanwhile, in the case using another commercial ether-based LiTFSI electrolyte with it, the LiFePO4 cathode (1.5 mAh cm−2)|Li metal cell also maintained long-term stability with high coulombic efficiency and the discharge capacity even with a small electrolyte amount and a high current density of 1.5 mA cm−2. By combining the surface analysis with quantum chemistry calculations, it is verified that the stabilization effect by introduction of this additive at the extreme condition was resulted from the formation of a robust and stable solid electrolyte interphase (SEI), in which the LiF and Li3N components could play a synergistic role in the improvement of SEI layer performance. Such a fluoropyridine molecule with good compatibility in the LMBs is expected to be a promising electrolyte additive for the next generation of LMBs.