CAJ | 학술논문

使用Nb2O5和Nb(OC6H5)5为铌源对LiFePO4/C中的锂位和铁位分别掺杂,采用碳热还原法合成掺杂Nb的磷酸铁锂系列材料.运用X射线衍射仪、扫描电镜、循环伏安、交流阻抗谱和恒电流充放电测试等对材料进行表征.结果表明:相比掺杂位置,铌源对材料的颗粒形貌和粒径分布影响更大,而颗粒大小对材料的电化学性能,尤其是大倍率性能的提高有重要作用；掺杂在Li位的Nb元素比在Fe位能更好的稳定晶体结构,从而有利于提高循环性能.
사용Nb2O5화Nb(OC6H5)5위니원대LiFePO4/C중적리위화철위분별참잡,채용탄열환원법합성참잡Nb적린산철리계렬재료.운용X사선연사의、소묘전경、순배복안、교류조항보화항전류충방전측시등대재료진행표정.결과표명:상비참잡위치,니원대재료적과립형모화립경분포영향경대,이과립대소대재료적전화학성능,우기시대배솔성능적제고유중요작용；참잡재Li위적Nb원소비재Fe위능경호적은정정체결구,종이유리우제고순배성능.
Nb-doped LiFePO4/C materials with different Nb sources and doping sites were synthesized by carbon thermal reduction method using Nb2O5 and Nb(OC6H5)5 as Nb source.The materials were characterized by XRD,SEM,cyclic voltammetry (CV),electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge test.The results indicate that Nb source has stronger effect on the particle morphology and size distribution than that of doping site,and the particle size has significant importance on electrochemical performance,especially under high discharge rate.Doping Nb in Li site can stabilize the crystal structure better than doping in Fe site,to improve cycling performance.