Engineering Wavy-Nanostructured Anode Interphases with Fast Ion Transfer Kinetics: Toward Practical Li-Metal Full Batteries

Fast Li-metal depletion and severe anode pulverization are the most critical obstacles for the energy-dense Li-metal full batteries using thin Li-metal anodes (<50 µm). Here, a wavy-nanostructured solid electrolyte interphase (SEI) with fast ion transfer kinetics is reported, which can promote high-efficiency Li-metal plating/stripping (>98% at 4 mAh cm −2 ) in conventional carbonate electrolyte. Cryogenic transmission electron microscopy (cryo-TEM) further reveals the fundamental relationship between wavy-nanostructured SEI, function, and the electrochemical performance. The wavy SEI with greatly decreased surface diffusion resistance can realize grain coarsening of Li-metal deposition and exhaustive dissolution of active Li-metal during the stripping process, which can effectively alleviate “dead Li” accumulation and anode pulverization problems in practical full cells. Under highly challenging conditions (45 µm Li-metal anodes, 4.3 mAh cm −2 high capacity LiNi 0.8 Mn 0.1 Co 0.1 O 2 cathodes), full cells exhibit significantly improved cycling lifespan (170 cycles; 20 cycles for control cells) via the application of wavy SEI.