Fluorocarbon interlayer enhancing fast ion transport for low-temperature lithium metal batteries

Lithium metal batteries optimized for low-temperature conditions are essential for use in cold climate applications. Nevertheless, they are hindered by the markedly reduced kinetics of lithium-ion transport in the vicinity of the lithium metal anode under low-temperature conditions. In contrast to the commonly used electrolyte engineering approaches, this study introduces a design strategy of using a functional fluorocarbon interlayer to reconstruct the surface of the lithium foil (Li@GF), aiming to effectively enhance the electrochemical reaction kinetics of the lithium metal anode at low temperatures. Extensive experimental and theoretical investigations demonstrate that the fluorocarbon interlayer exhibits improved lithiophilicity and provides multiple ionic conductive pathways, thereby promoting uniform and rapid lithium ion transport at the interface. The Li(Ni_0.8Co_0.1Mn_0.1)O₂ (NCM811)||Li@GF full cells exhibit a commercial-grade capacity of 84.34 mAh g^-1 and maintain an impressive capacity retention of 93.3 % after 300 cycles at -40 °C. The strategic design of a functional interphase aimed at improving ion transfer kinetics offers new perspectives for the advancement of lithium metal batteries characterized by high areal capacity and prolonged longevity under low-temperature conditions.