The inhibited Li dendrite growth via bulk/liquid dual-phase modulation

Li metal is a potential anode material for the next generation high-energy-density batteries because of its high theoretical specific capacity. However, the inhomogeneous lithium dendrite growth restrains corresponding electrochemical performance and brings safety concerns. In this contribution, the Li3Bi/Li2O/LiI fillers are generated by the in-situ reaction between Li and BiOI nanoflakes, which promises corresponding Li anodes (BiOI@Li) showing favorable electrochemical performance. This can be attributed to the bulk/liquid dual modulations: (1) The three-dimensional Bi-based framework in the bulk-phase lowers the local current density and accommodates the volume variation; (2) The LiI dispersed within Li metal is slowly released and dissolved into the electrolyte with the consumption of Li, which will form I-/I3- electron pair and further reactivate the inactive Li species. Specifically, the BiOI@Li//BiOI@Li symmetrical cell shows small overpotential and enhanced cycle stability over 600 h at 1 mA cm-2. Matched with an S-based cathode, the full Li-S battery demonstrates desirable rate performance and cycling stability.