Coupling of ion-conducting interphase with lithiophilic-solid-oxide-electrolyte interlayer toward fast-charging lithium metal batteries

•Functionalized garnet by ATMP to protect Li.•Conducting interphase with lithiophilic interlayer for Li metal are designed.•Ultrahigh plating/stripping current of 10 mA cm−2 and 10 mAh cm−2 are achieved.•Remarkable Coulombic efficiency of 99.8% is presented.•3.6 mAh cm−2Li||NCM811 batteries can be cycled at 1.8 mA cm−2. The uncontrollable dendritic Li growth and limited Coulombic efficiency have long impeded the implementation of fast-charging lithium metal batteries. Contrary to the widely accepted attempt of using a sintering dense ceramic electrolyte to realize dendrite-free deposition, we report a coupling architecture of ion-conducting-Li3PO4-Li3N interphase with lithiophilic-solid-oxide-electrolyte interlayer for Li-metal anode using a reactive lithiophilic solid oxide electrolyte (RLSE) rather than dense ceramics. The synergistic interphase and protection layer can facilitate the Li-ion transport and enhance the lithiophilicity. As a result, an ultrahigh Li plating/stripping current density of 10 mA cm−2 and areal capacity of 10 mAh cm−2 for over 1000 h, and a remarkable Coulombic efficiency of 99.8 % are achieved simultaneously. Moreover, the use of interphase-interlayer synergistic protection enables a stable long-term 3000-cycling of Li||Li4Ti5O12 cell at 2C rate. More importantly, high-current–density (e.g. 1.8 mA cm−2) cycling of Li||LiNi0.8Co0.1Mn0.1O2 batteries with a practical area capacity of 3.6 mAh cm−2 is achieved in both carbonate and quasi-solid electrolytes. This study demonstrates an alternative approach of solid oxide electrolytes to stabilize Li-metal anode and enable fast-charging lithium metal batteries.