Intrinsic lithiophilic carbon host derived from bacterial cellulose nanofiber for dendrite-free and long-life lithium metal anode

Although lithium metal is considered a promising anode for advanced Li-S and Li-air batteries, the uncontrolled dendrite growth and infinite volume change impede its practical application. Herein, we report an ideal framework composed of carbonized bacterial cellulose (CBC) nanofibers, which shows intrinsic lithiophilicity to molten lithium without any lithiophilic surface modification. The wetting behavior of molten lithium can be significantly improved because its surface functional groups provide thermodynamical driving force, and the high surface roughness derived from nanocracks leads to rapid infusion in kinetics. The hybrid anode exhibits long cycle life up to 2000 h and excellent deep stripping–platting capacity up to 20 mAh·cm−2. When the anode is assembled with LiFePO4 cathode, the full cell delivers a good cycling stability up to 700 cycles. This is attributed to the intrinsic lithiophilic scaffold, which can not only lower the nucleation barrier of Li and provide uniform nucleation sites for stable Li stripping/plating, but also offer interspace to accommodate volume fluctuation of lithium during long cycling. This work provides a new manner to achieve a series of intrinsic lithiophilic carbon skeletons based on the large family of biomass materials and organic materials.