Investigation of the Na Intercalation Mechanism into Nanosized V2O5/C Composite Cathode Material for Na-Ion Batteries

摘要: There is a significant interest to develop high-performance and cost-effective electrode materials for next-generation sodium ion batteries. Herein, we report facile synthesis method nanosized V2O5/C composite cathodes their electrochemical performance as well energy storage mechanism. The exhibits discharge capacity of 255 mAh g(-1) at current density 0.05 C, which surpasses that previously reported layered oxide materials. Furthermore, the shows good rate capability; 160 1 C. reaction mechanism V2O5 upon insertion/extraction investigated using ex situ X-ray diffraction (XRD) synchrotron based near edge absorption fine structure (NEXAFS) spectroscopy. Ex XRD result fully discharged state reveals appearance NaV2O5 major phase with minor Na2V2O5 phase. Upon insertion into array parallel ladders V2O5, it was confirmed lattice parameter c increased by 9.09%, corresponding increase in unit-cell volume 9.2%. NEXAFS results suggest charge compensation during de/sodiation process accompanied reversible changes oxidation vanadium (V(4+) ↔ V(5+)).