Reorganizing electronic structure of Li3V2（PO4）3 using polyanion（BO3）^3-：towards better electrochemical performances

• Published in: 稀有金属：英文版 2017, Vol.36 (5), p.397-402
• Main Author: Yu Li Ying Bai Zhi Yang Zhao-Hua Wang Shi Chen Feng Wu Chuan Wu
• Format: Article
• Language: English
• Subjects: X-射线衍射; 循环伏安法; 扫描电子显微镜; 掺杂改性; 电化学性能; 电子结构; 聚阴离子; 重组
• ISSN: 1001-0521; 1867-7185

Doping modification of electrode materials is a sought-after strategy to improve their electrochemical performance in the secondary batteries field. Herein,polyanion（BO3）^3-doped Li3V2（PO4）3 cathode materials were successfully synthesized via a wet coordination method. The effects of（BO3）^3- doping content on crystal structure, morphology and electrochemical performance were explored by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, cyclic voltammetry（CV） and electrochemical impedance spectroscopy（EIS）. All the asprepared samples have the same monoclinic structure;among them, Li3V2（PO4）（2.75）（BO3）（0.15） sample has relatively uniform and optimized particle size. In addition, this sample has the highest discharge capacity and the best cycling stability, with an initial discharge capacity of 120.4mAh·g^-1, and after 30 cycles at a rate of 0.1C, the discharge capacity still remains 119.3 mAh·g^-1. It is confirmed that moderate polyanion（BO3）^3- doping can rearrange the electronic structure of the bulk Li3V2（PO4）3,lower the charge transfer resistance and further improve the electrochemical behaviors.