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

ABSTRACT Garnet‐type solid‐state electrolyte Li _6.4 La ₃ Zr _1.4 Ta _0.6 O ₁₂ (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 HNO ₃ etching. Owing to the hydrophobicity of the C ₁₂ H ₂₅ ‐ 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 LiNO ₃ in the surface of PLLZTO, a 3D ionic conductor interface containing Li ₃ N/LiN _x O _y /Li ₂ O (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 cm ² 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.