Dendrite‐Free Dual‐Phase Li‐Ba Alloy Anode Enabled by Ordered Array of Built‐in Mixed Conducting Microchannels

Abstract The development and application of lithium (Li) anode is hindered by volumetric variation, dendritic Li growth, and parasitic reactions. Herein, a dual‐phase Li‐barium (Ba) alloy with self‐assembled microchannels array is synthesized through a one‐step thermal fusion method to investigate the inhibition effect of lithiophilic composite porous array on Li dendrites. The Li‐rich Li‐Ba alloy (BaLi24) as composite Li electrode exhibits an ordered porous structure of BaLi₄ intermetallic compound after delithiation, which acts as a built‐in 3D current collector during Li plating/striping process. Furthermore, the lithiophilic BaLi₄ alloy scaffold is a mixed conductor, featuring with Li⁺ ions diffusion capability, which can efficiently transport the reduced Li to the interior of the electrode structure. This unique top‐down growth mode can effectively prohibit Li dendrites growth and improve the space utilization of 3D electrode structure. The spin‐polarized density functional theory (DFT) calculations suggest that the absorption capability of BaLi₄ benefits the deposition of Li metal. As a result, the cell performance with the dual‐phase Li‐Ba alloy anode is significantly improved.