Synthesis of Rod-Like Sb2Se3@MWCNT as Conductive-Additive Free Anode for Sodium-Ion Batteries

Abstract

Antimony selenide (Sb₂Se₃) is a promising electrode material for sodium-ion batteries (SIBs) due to its high theoretical capacity. However, volume expansion during sodiation/desodiation and the low conductivity of Sb₂Se₃ reduce the electrochemical performance. Herein, we synthesized Sb₂Se₃ nanorods (NRs) and combined them with multi-walled carbon nanotubes (MWCNTs) using one-step composite process to address these issues. MWCNTs can accommodate volume expansion and provide high conductivity. The fabricated Sb₂Se₃ NRs@MWCNT electrode exhibits improved cycle performance and cyclic stability without additional conductive carbons. The Sb₂Se₃ NRs@MWCNT electrode showed an enhanced specific capacity of 440 mAhg⁻¹ at a current density of 0.1 Ag⁻¹, compared to 220 mAhg⁻¹ for the Sb₂Se₃ NRs electrode. Additionally, it exhibited good stability at high current density. The in-situ electrochemical impedance spectroscopy (EIS) and Galvanostatic intermittent titration technique (GITT) were used to estimate the electrochemical properties and kinetics of Sb₂Se₃ NRs@MWCNT. These results showed that Sb₂Se₃ NRs@MWCNT have the potential as a conductive-free anode material in SIBs.