Multifunctional organic corncob lignin and inorganic lithium nitride composite films as artificial protective layer to achieve high-performance Li metal anodes

Lithium (Li) metal batteries are deemed to an outstanding candidate of next-generation energy storage instruments due to their low electrochemical potential as well as high theoretical capacity. Nonetheless, the uncontrolled dendrite growth of Li and side reaction occurrence of Li metal anodes hamper their application. In this work, we fabricated an organic corncob lignin /inorganic lithium nitride composite layer by a facile in-situ coating method. For one thing, the organic corncob lignin layer can avoid direct contaction of Li with electrolyte, reduce the occurrence of undesirable reactions, and enhance the stability of electrode/electrolyte interface. For another, the component of inorganic lithium nitride in the composite layer can facilitate the ion transportation between electrolyte and Li metal anodes, increase mechanical properties of the film, decrease the nucleation overpotential, and eventually suppress the growth of Li dendrite. The Li metal anodes with composite protective layers exhibit good cycling property of 2000 h at 1.5 mA cm−2 with 1.5 mAh cm-2. The Li-S full batteries assembled with Li metal anodes coated by composite protective layers show good cycling performance of 513.7 mAh g-1 after 300 cycles in contrast to bare Li. This study provides a simple coating method to fabricate artificial solid electrolyte interphase layer and promotes to realizing stable and safe Li-metal batteries and recycling the lignin from industrial waste.