Poor reversibility of the Li anode and uncontrolled Li dendrite growth lead to the low Coulombic efficiency and serious security risks, which hinder the practical application of lithium (Li) metal batteries. Herein, we report an artificial solid electrolyte interphase (SEI) strategy for repressing Li dendrite growth and facilitating uniform Li deposition. The N-vinyl carbazole (NVK) was polymerized on the Li anode surface to form artificial SEI film. Such SEI film generates highly Li⁺ conductive lithium nitride (Li₃N) to boost uniform Li⁺ flux and then facilitates uniform Li deposition on the Li anode. Therefore, the Li||Li symmetric cells showed excellent cycling performance with 350 cycles at 1.0 mA/cm². Meanwhile, the Li||LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) batteries also achieved a higher cycling performance with a capacity retention of 87.5% after 150 cycles. This work provides a simple and effective strategy to solve the problem of dendrites in the Li metal battery.

High-voltage lithium metal batteries based on high-nickel layered oxide cathodes are attractive due to their high energy density. However, they suffer from a severe decline in capacity at low temperatures, and the limited voltage range of low-temperature electrolytes fails to meet their application. To address this issue, we developed low-temperature carbonated electrolytes for lithium metal batteries with robust LiP_xO_yF_z- and LiF-rich Li⁺-conductive electrode–electrolyte interphases. The dual interphases with a LiPO₂F₂ additive could accelerate Li⁺ migration, reduce impedance, prevent electrolyte consumption, alleviate cathode degradation, and even mitigate the severe polarization of the Li anode at −50 °C. As a result, a 4.6-V Li||NCM811 cell with an optimized electrolyte sustained 160 cycles before reaching the 80% threshold and sustained a 92% capacity retention rate (139.9 mAh g⁻¹) at 20 mA g⁻¹/−30 °C after 50 cycles. Moreover, it could deliver 118 mAh g⁻¹ even at 20 mA g⁻¹/−50 °C.