Stable lithium metal batteries enabled by Al-Li/LiF composite artificial interfacial layer

Lithium metal anode represents the ultimate solution for next-generation high-energy-density batteries but is plagued from commercialization by side reactions, substantial volume fluctuation, and the notorious growth of lithium dendrites. These hazardous issues are further aggravated under real-world conditions. In this study, a stable Al-Li/LiF artificial interphase with rapid ion transport pathways is created through a one-step chemical pretreatment process, effectively addressing these challenges simultaneously. As a consequence, the composite interfacial layer exhibits exceptional ionic conductivity, mechanical strength, and electrolyte wettability, ensuring swift Li⁺ transfer diffusion while suppressing lithium dendrite growth. Remarkably, the Al-Li/LiF symmetric cell provides a cycle life exceeding 2300 h with a low polarization at 0.5 mA·cm⁻². Furthermore, its enhanced cycling stability and capacity retention as well as capacity utilization stability pairing with LiFePO₄ and LiNi_0.8Co_0.1Mn_0.1O₂ cathodes, highlighting the proposed approach as a promising solution for practical Li metal batteries.