Multifunctional and Seamlessly Integrated Soft/Rigid Interphase Realizing a Stable Lithium-Metal Anode for a High-Performance Lithium-Metal Battery under a Lean Electrolyte

Although the organic/inorganic hybrid artificial solid electrolyte interphase (SEI) has been proven to effectively optimize the interfacial stability of the Li-metal anode, its rational construction and coupling mechanism are still challenging. In this work, a multifunctional and seamlessly integrated artificial interphase with a synergistic soft (PVDF-HFP)/rigid (Li₃Sb/LiF) feature is designed to stabilize Li anode for a high-performance Li-metal battery under a lean electrolyte. As evidenced theoretically and experimentally, the soft PVDF-HFP polymer is used to adaptively tune the surface current density near the Li/electrolyte interface and substantially prevent the electrolyte solvent from being consumed, while the rigid Li₃Sb/LiF particles embedded in the PVDF-HFP polymer also can guarantee efficient Li⁺ transport and fast Li nucleation/deposition with a low energy barrier. As a result, even at 20 mA cm^-2/2 mAh cm^-2, the modified Li anode can provide excellent cycling performance in Lia∥Li symmetrical cells over 1000 cycles. Most impressively, it also enables the LiNi_0.8Co_0.1Mn_0.1O₂ (4.4 mAh cm^-2)a∥Li (50 μm) full cell to realize superior cycling stability under harsh conditions (low N/P ratio ≈ 2.2 and lean electrolyte 12 μL mAh^-1) compared to the bare Li anode, which shows a high average CE of 99.7% and high capacity retention of 79.2% after 100 cycles, demonstrating its great potential in practical Li-metal batteries. This work proposes an adaptive artificial interphase with synergistic soft/rigid features and realizes the practical lean-electrolyte Li-metal batteries.