Three‐Dimensional High‐Efficiency Superlithiophilic Interface Toward Air‐Stable Garnet‐Based All‐Solid‐State Lithium Metal Batteries

Garnet-type solid-state electrolyte Li6.4La₃Zr1.4Ta0.6O₁₂ (LLZTO) is regarded as one of the most promising electrolytes due to its exceptional overall performance. However, the development of garnet-based all-solid-state lithium metal batteries (ASSLMBs) is significantly impeded by the poor air stability of LLZTO and the uneven contact of Li/LLZTO. In this work, a uniformly porous electrolyte (PLLZTO) is fabricated via sodium dodecyl benzene sulfonate (SDBS) assisted HNO₃ etching. Owing to the hydrophobicity of the C₁₂H₂₅- chain of SDBS, the storage time of PLLZTO in air is increased to more than 7 days. By adsorbing and filling graphene oxide quantum dots and LiNO₃ in the surface of PLLZTO, a 3D ionic conductor interface containing Li₃N/LiNxOy/Li₂O (LNO@PLLZTO) is constructed by in situ reaction with lithium. Benefiting from the LNO@PLLZTO interface, Li|LNO@PLLZTO|Li achieves a low interfacial impedance of 4 Ω cm² and a high critical current density of 1.5 mA cm⁻², demonstrating stable cycling for 3000 h at 0.2 mA cm⁻². The assembled ASSLMBs with polyethylene oxide (PEO)-based functional layer retains 92% capacity retention after 250 cycles at 1 C. This work not only significantly enhances the air stability of LLZTO but also achieves an ultra-lithiophilic interface, thus laying a foundation for the realization of high-performance ASSLMBs.