Chemically Crushed Wood Cellulose Fiber towards High-Performance Sodium-Ion Batteries

Carbon materials have attracted great interest as an anode for sodium-ion batteries (SIBs) due to their high performance and low cost. Here, we studied natural wood fiber derived hard carbon anodes for SIBs considering the abundance and low cost of wood. We discovered that a thermal carbonization of wood fiber led to a porous carbon with a high specific surface area of 586 m² g^–1, while a pretreatment with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) could effectively decrease it to 126 m² g^–1. When evaluating them as anodes for SIBs, we observed that the low surface area carbon resulted in a high initial Coulombic efficiency of 72% compared to 25% of the high surface area carbon. More importantly, the low surface area carbon exhibits an excellent cycling stability that a desodiation capacity of 196 mAh g^–1 can be delivered over 200 cycles at a current density of 100 mA g^–1, indicating a promising anode for low-cost SIBs