Growing single-crystalline seeds on lithiophobic substrates to enable fast-charging lithium-metal batteries

Controlling the nucleation and growth of lithium metal is essential for realizing fast-charging batteries. Here we report the growth of single-crystalline seeds that results in the deposition of dense lithium, even at high current densities. Contrary to the widely accepted practice of using a lithiophilic surface to achieve dendrite-free deposition, we employ a lithiophobic surface made of a nanocomposite of LiF and Fe to deposit hexagonal crystals, which induce subsequent dense lithium deposition. The nanocomposites have uniform Fe sites for nucleation while LiF enables rapid lithium transport. A cell using a 3 mAh cm −2 LiNi 0.8 Co 0.1 Mn 0.1 O 2 (LiNMC811) cathode, onefold excess of lithium and 3 g Ah −1 electrolyte cycles at a 1 C rate for more than 130 cycles with 80% capacity retention, a 550% improvement over the baseline cells. Our findings advance the understanding of lithium nucleation and pave the way for realizing high-energy, fast-charging Li-metal batteries.