Sb_1–xSe_x Nanoparticles as Durable and Stable Anode Materials for Sodium-Ion Batteries

Antimony-based electrodes have earned a place among anodes for sodium-ion batteries (SIBs) on account of their high specific capacity and appropriate reaction potential. However, significant volume changes during charge/discharge cycles directly lead to poor cycling ability, prohibiting their further practical application. Doping is recognized as a valid approach to tuning the electrochemical properties of electrodes for better electrochemical performances. In this work, Se-doped Sb solid solution (Sb1-xSex) nanoparticles are reported as a variety of anode materials for SIBs via a straightforward solvothermal method. The nanoparticles are uniformly distributed with a small size of about 20 nm. The diffusion properties of Na+ are studied by the galvanostatic intermittent titration technique (GITT), and the coefficient is acquired by calculation to be 1.8 × 10–12 cm2 s–1. The electrochemical measurement results show that the nanoparticle electrode yields reversible capacities of 514, 500, 464, and 313 mAh g–1 at 0.5, 1, 2, and 5 A g–1, respectively. An initial charging specific capacity of 556.3 mAh g–1 could be stable for 100 cycles at 100 mA g–1, retaining up to 96.8% of battery capacity. It is believed that a solution is provided based on our findings to polish the electrochemical characteristics applied in SIBs by means of doping.