Antimony Anchored with Nitrogen-Doping Porous Carbon as a High-Performance Anode Material for Na-Ion Batteries

Antimony represents a class of unique functional materials in sodium-ion batteries with high theoretical capacity (660 mA h g^-1). The utilization of carbonaceous materials as a buffer layer has been considered an effective approach to alleviate rapid capacity fading. Herein, the antimony/nitrogen-doping porous carbon (Sb/NPC) composite with polyaniline nanosheets as a carbon source has been successfully achieved. In addition, our strategy involves three processes, a tunable organic polyreaction, a thermal annealing process, and a cost-effective reduction reaction. The as-prepared Sb/NPC electrode demonstrates a great reversible capacity of 529.6 mA h g^-1 and an outstanding cycling stability with 97.2% capacity retention after 100 cycles at 100 mA g^-1. Even at 1600 mA g^-1, a superior rate capacity of 357 mA h g^-1 can be retained. Those remarkable electrochemical performances can be ascribed to the introduction of a hierarchical porous NPC material to which tiny Sb nanoparticles of about 30 nm were well-wrapped to buffer volume expansion and improve conductivity.