钒掺杂LiCoPO4正极材料的制备及电化学性能

摘要

采用聚乙二醇辅助的溶胶-凝胶法制备了锂离子电池复合正极材料LiCo1-xVxPO4/C(x=0、0.03和0.05).X射线衍射(XRD)表明掺杂的V进入了LiCoPO4晶格内部.扫描电镜(SEM)和透射电镜(TEM)显示LiCo0.97V0.03PO4/C的粒径分布在200～700nm之间,颗粒表面包覆一层约30nm厚的碳层.在0.1C倍率下,LiCo0.97V0.03PO4/C和LiCoPO4/C的首次放电容量分别为111和70mAh/g.掺杂V不仅能够改善材料的循环稳定性而且提高了材料的放电电压平台.%LiCo1-x Vx PO4/C (x= 0, 0. 03 and 0.05) composites were prepared via a poly (ethylene glycol ) assisted sol-gel method and exploited as cathode materials for lithium ion batteries. X-ray diffraction (XRD) patterns of the samples indicate that vanadium is introduced into LiCoPO4 matrix structure. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the LiCo0.97 V0.03 PO4/C displays a particle distribution from 200 to 700 nm and is also coated with a carbon layer of about 30nm in thickness. The initial discharge capacity of LiCo0. 97 V0.03 PO4/C and LiCoPO4/C are 111 and 70mAh/g, respectively. The vanadium modification not only improves the cyclic stability but also enhances the discharge voltage plateaus.