In situ anchoring 2D hexagonal Zn-MOF on MXene toward robust anode-less 5 V-class Li metal batteries

Anode-less 5 V-class lithium metal batteries (LMBs) promise high energy density and safety yet, in practice, face critical challenges including dendrite growth, interfacial instability, pulverization associated with "dead" lithium accumulation, and energy density compromise from the use of heavy copper collector. Here, we demonstrate an elaborate design of two-dimensional hexagonal zinc-containing metal-organic framework anchored on conductive titanium carbide (Ti₃C₂T_x) MXene sheets (MX/2D-Zn-MOF) as a three-dimensional lightweight host for anode-less 5 V-class LMBs. The abundant nitrogen/fluorine/zinc-rich lithiophilic sites effectively decrease lithium nucleation energy barriers, ensure uniform lithium deposition, and stabilize solid electrolyte interphase. The interconnected three-dimensional framework further guides uniform lithium deposition by spatially homogenizing lithium ion flux and reducing local current density as well as offers sufficient space to alleviate structural change, thus affording structural integrity against pulverization. As a result, the MX/2D-Zn-MOF host demonstrates uniform lithium deposition, reversible lithium plating and stripping behavior, and stable cycling performance (~1800 hours at 1.0 milliamperes per square centimeter and 5.0 milliampere hours per square centimeter). Impressively, the assembled anode-less 5 V-class lithium metal pouch cell delivers stable cycling performance and high energy density.