Scalable fabrication of antimony nanoparticles confined in a porous carbon framework for high-performance sodium-ion batteries

Abstract Engineering of carbon/metal nanocomposites with small metal particles is promising for the development of alloy-type anodes. Herein, an Sb@C composite was developed from a commercial potassium antimony tartrate precursor using a scalable pyrolysis method. Ultrafine Sb nanoparticles are confined within a porous carbon framework, which substantially facilitates the diffusion of Na-ion/electrons and effectively alleviates the charging/discharging induced volume change. The obtained Sb@C material displays excellent electrochemical performance for Na+ storage. The Na+ diffusion behavior of Sb@C was comprehensively investigated using various methods, and its gas evolution during the discharge/charge was monitored via online mass spectrometry. Then, Sb@C was assembled into full cells. During discharge/charge processes, the Na3V2(PO4)2F3/Sb@C full cells delivered a competitive working voltage of 2.95 V and a capacity retention of 93.4% (50 cycles @ 0.2 A g−1). Considering its facile preparation method from a commercial precursor, the Sb@C composite can potentially realize a large-scale application of sodium-ion batteries.