Natural Wood Structure Inspires Practical Lithium–Metal Batteries

High-energy-density lithium (Li)-metal batteries (LMBs) suffer from short life spans caused by "dead" Li and dendrites. The generation of a stable, artificial solid–electrolyte interphase (SEI) for spatially homogeneous Li-ion flux and rapid Li-ion transport will correspondingly solve these issues. For the first time, we exfoliate 10 nm thick, pit-membrane-like nanowood using a top-down method and designed a natural-wood-structured interface as an artificial SEI. The artificial SEI possesses nanochannels between the naturally assembled parallel cellulose molecules, which regulate Li deposition uniformity. Meanwhile, the interconnected micropores and abundant lithiophilic groups on the nanowood facilitate rapid Li-ion migration. Nanowood-protected LMBs delivered a remarkable capacity of ∼140 mAh·cm–2 and high average Coulombic efficiency of 99.6% for 800 cycles. This nanowood-based, high-performance, scalable, biomimetic SEI with ion-flux regulation represents an attractive solution to the short life span of practical LMBs.