Sb_1–<i>x</i>Se<i>_x</i> Nanoparticles as\nDurable and Stable Anode Materials\nfor Sodium-Ion Batteries

Abstract

Antimony-based\nelectrodes have earned a place among anodes for\nsodium-ion batteries (SIBs) on account of their high specific capacity\nand appropriate reaction potential. However, significant volume changes\nduring charge/discharge cycles directly lead to poor cycling ability,\nprohibiting their further practical application. Doping is recognized\nas a valid approach to tuning the electrochemical properties of electrodes\nfor better electrochemical performances. In this work, Se-doped Sb\nsolid solution (Sb_1-xSe_x) nanoparticles are\nreported as a variety of anode materials for SIBs via a straightforward\nsolvothermal method. The nanoparticles are uniformly distributed with\na small size of about 20 nm. The diffusion properties of Na⁺ are studied by the galvanostatic intermittent titration technique\n(GITT), and the coefficient is acquired by calculation to be 1.8 ×\n10^–12 cm² s^–1. The\nelectrochemical measurement results show that the nanoparticle electrode\nyields reversible capacities of 514, 500, 464, and 313 mAh g^–1 at 0.5, 1, 2, and 5 A g^–1, respectively. An initial\ncharging specific capacity of 556.3 mAh g^–1 could\nbe stable for 100 cycles at 100 mA g^–1, retaining\nup to 96.8% of battery capacity. It is believed that a solution is\nprovided based on our findings to polish the electrochemical characteristics\napplied in SIBs by means of doping.