High-entropy selenide enables gradient ionic potential and stable interfacial chemistry for anode-free lithium...

Lithium-free anodes can significantly enhance the energy density and simplify the structure of batteries by eliminating conventional anode materials. However, uneven lithium deposition often leads to dendrite growth and interfacial instability, severely compromising their cycling performance. Here, we construct a high-entropy selenide nanocomposite ((VZrNbMoW)Se₂, HESe) on a three-dimensional carbon fiber scaffold through a localized high-concentration vapor-phase selenization strategy. This architecture preserves the conductive scaffold while establishing a compositionally graded surface that reduces Li⁺ diffusion barriers, eliminates local tip effects, and promotes lateral planar epitaxial growth of lithium. Such a gradient interfacial design further directs the formation of a stable, multilayered solid-electrolyte interphase featuring a LiF/Li₂O-rich inorganic inner layer and an organic-rich outer layer, enabling synergistic regulation of deposition morphology and interfacial chemistry. As a result, the Li|HESe/CF half-cell delivers stable cycling for 1000 cycles with an average Coulombic efficiency of 99.5% under 20 mA cm^-2/1 mAh cm^-2. The LFP||HESe/CF full cell achieves 89.82% capacity retention after 200 cycles at 1.5C, corresponding to a low decay rate of only 0.0509% per cycle. This study provides an effective Li deposition regulation strategy via high-entropy selenide in anode-free lithium metal batteries.