Fabrication of Tri‐Phase Lithium Alloy in Seconds via an Implosion‐Popcorn Reaction Toward Stable Lithium Metal Batteries

Introducing non‐lithium components to fabricate lithium‐based alloy anodes has emerged as a paramount strategy to enhance the processability and stability of lithium metal batteries. However, conventional fabrication suffers from the sluggish wetting kinetics of lithium with non‐lithium components, inducing severe phase heterogeneity and component agglomeration. Herein, we report an ultrafast, spontaneous implosion‐popcorn reaction that explosively disintegrates centimeter‐scale precursor ingots into ultra‐fine particles within seconds, yielding a uniformly dispersed tri‐phase alloy with an interpenetrating network of Fe, Li 3 P, and Li. The as‐obtained lithium alloy exhibits a significantly enhanced Young's modulus and can be processed into different forms, including coatable slurries, self‐standing foils, and active powders. This fabrication method shifts from traditional passive alloying to an active, highly efficient, and homogenous approach. When used as an anode, the homogeneous Li/Fe/Li 3 P architecture facilitates interfacial Li‐ion transfer and regulates initial Li nucleation, thereby promoting dense and uniform Li growth and enabling a cycling lifespan of over 3000 h, together with improved full‐cell stability.