Mesoporous Gold Film with Surface Sulfur Modification to Enable Dendrite-Free Lithium Plating/Stripping for Long-Life Lithium Metal Anodes.

Abstract

The formation of a lithiophilic phase is an effective method to inhibit the growth of lithium dendrites and obtain high-performance Li metal anodes (LMAs). Nonetheless, previous studies have overlooked the underlying mechanistic studies that modulate the structure of the lithiophilic phase as well as lithiophilicity. A self-supporting sulfur-modified mesoporous gold film on nickel foam (SMGF@NF) for LMAs is created with mesoporous structure, which can provide sufficient active sites for uniform lithium deposition. The synergistic promotion of lithiophilic gold and sulfurleads to uniform lithium nucleation and induces consistent lithium removal during lithium stripping. The doping of S promotes the decomposition of bistrifluoromethanesulfonimide lithium saltto generate lithium fluorde, thus forming a more stable solid electrolyte interface. Combining the multifaceted advantages of SMGF@NF, its lithium-plated electrode can achieve ultralong cycle life in symmetrical batteries (over 1000h at 0.5mA cm-2 and 1 mAh cm-2 ) and ultralow overpotential (≈10mV). Meanwhile, the Li-SMGF@NF||LiFePO4 full cell achieves a high cycling performance and rate capability (92.4% capacity retention after 1000 cycles at 5 C). The study probes into the composite electrode surface composition and structure, revealing the mechanism of high-performance LMAs.