Preparation of NaV_(1-x)AlxPO_4F cathode materials for application of sodium-ion battery  

作　　者：刘志明 王先友 王莹 唐安平 杨顺毅 何亮甫 

机构地区：[1]School of Chemistry,Xiangtan University [2]School of Chemical Engineering and Pharmacy,Wuhan Institute of Technology

出　　处：《中国有色金属学会会刊：英文版》2008年第2期346-350,共5页Transactions of Nonferrous Metals Society of China

基　　金：Project(50472080)supported by the National Natural Science Foundation of China;Projects(04JJ3040,05JJ20013)supported by the Natural Science Foundation of Hunan Province,China;Project(BK2003092)supported by the Natural Science Foundation of Jiangsu Province,China

摘　　要：The effects of Al doping on the electrochemical properties of NaVPO4F as a cathode material for sodium-ion batteries were investigated.Al-doped NaV1-xAlxPO4F(x=0,0.02)samples were prepared by a simple high temperature solid-state reaction involving VPO4 and NaF for the application of cathode material of sodium-ion batteries.The crystal structure and morphology of the material were studied by Flourier-infrared spectrometry(FT-IR),X-ray diffractometry(XRD)and scanning electron microscopy(SEM).The results show that NaV1-xAlxPO4F(x=0,0.02)has a typical monoclinic structure.The effects of Al doping on the performance of the cathode material were analyzed in terms of the crystal structure,charge-discharge curves and cycle performance.It is found that NaV0.98Al0.02PO4F shows an improved cathodic behavior and discharge capacity retention compared with the undoped samples in the voltage range of 3.0-4.5 V.The electrodes prepared from NaV0.98Al0.02PO4F deliver an initial discharge capacity of 80.4 mA·h/g and an initial coulombic efficiency of 89.2%,and the capacity retention is 85%after 30th cycle. Though the Al-doped samples have lower initial capacities,they show better cycle performance than Al-free samples.The effects of Al doping on the electrochemical properties of NaVPO4F as a cathode material for sodium-ion batteries were investigated. Al-doped NaV1-xAlxPO4F （x=0, 0.02） samples were prepared by a simple high temperature solid-state reaction involving VPO4 and NaF for the application of cathode material of sodium-ion batteries. The crystal structure and morphology of the material were studied by Flourier-infrared spectrometry（FT-IR）, X-ray diffractometry（XRD） and scanning electron microscopy（SEM）. The results show that NaV1-xAlxPO4F （x=0, 0.02） has a typical monoclinic structure. The effects of Al doping on the performance of the cathode material were analyzed in terms of the crystal structure, charge-discharge curves and cycle performance. It is found that NaV0.98Al0.02PO4F shows an improved cathodic behavior and discharge capacity retention compared with the undoped samples in the voltage range of 3.0-4.5 V. The electrodes prepared from NaV0.98Al0.02PO4F deliver an initial discharge capacity of 80.4 mA.h/g and an initial coulombic efficiency of 89.2%, and the capacity retention is 85% after 30th cycle. Though the Al-doped samples have lower initial capacities, they show better cycle performance than Al-free samples.

关 键 词：铝合金 钠电池 阴极 原料 

分 类 号：TM912[电气工程—电力电子与电力传动]