Coal tar pitch-based carbon composited Sb2Se3 microrod anode toward superior sodium storage performance

Antimony selenide (Sb₂Se₃) with low cost and high theoretical capacity has been explored as a potential alternative anode for sodium ion batteries. However, the large volumetric variation and sluggish dynamics of Sb₂Se₃ lead to unsatisfactory long-term cycling life and inferior rate performance. In order to resolve these issues, we proposed a fabrication of Sb₂Se₃ coated by N-doped carbon derived from coal tar pitch (CTP) by a facile solvothermal method followed by annealing process. The reasonable content of CTP can accommodate the volume expansion, hinder the pulverization and accelerate the charge transfer of Sb₂Se₃ upon the cycling process. As a result, the Sb₂Se₃/CTP6 electrode exhibits superior long cycling property with desodiation/sodiation of 129.2(130.6) mAh g^?1 after 400 cycles at high current density of 5 A g^?1 and outstanding rate performance. The XPS spectrum tests verify the decomposition of Sb₂Se₃ during the cycling in the first time and demonstrate the CTP can effectively enhance the structural stability of Sb₂Se₃. The ex-situ XRD is also utilized to reveal the Na⁺ storage mechanism and phase transition. This work offers a new modification for enhancing the structural stability of alloy-type anode materials.