摘要
本文引入离子半径较大的Bi^(3+)作为Na_(3)V_(2)(PO_(4))_(2)F_(3)中V位的掺杂物,同时协同碳包覆的改性作用,采用溶胶-凝胶法合成了Na_(3)V_(1.95)Bi_(0.05)(PO_(4))_(2)F_(3)/C聚阴离子型正极材料。电化学测量结果表明,在电压范围为2.3~4.3V、电流密度为0.1A·g^(-1)的条件下充放电时,Na_(3)V_(1.95)Bi_(0.05)(PO_(4))_(2)F_(3)/C材料的初始充/放电比容量为107.4/102.3 mAh·g^(-1),初始库伦效率为95%。在0.1、0.2、0.5、1.0、0.1 A·g^(-1)的电流密度下进行交替循环充放电时,材料的放电比容量分别为102.3、96.0、91.4、85.6、96.5 mAh·g^(-1),表现出良好的倍率性能。与未掺杂的Na_(3)V_(2)(PO_(4))_(2)F_(3)相比,Na_(3)V_(1.95)Bi_(0.05)(PO_(4))_(2)F_(3)/C的比容量提高了约20%。
A polyanionic cathode material Na_(3)V_(1.95)Bi_(0.05)(PO_(4))_(2)F_(3)/C was synthesized via sol-gel method,in which,the Bi^(3+)ion with larger radius than that of V^(3+)Fion was used as the dopant and doped in the V position of the pristine Na_(3)V_(2)(PO_(4))_(2)F_(3) material,and the carbon generated from calcination of citric acid was simultaneously coated on the particle surface.Results showed that the as prepared Na_(3)V_(1.95)Bi_(0.05)(PO_(4))_(2)F_(3)/C cathodes exhibited an initial specific capacity of 107.4/102.3 mAh/g with a coulomb efficiency of 95% under the measurement conditions of 2.3~4.3V and 0.1A/g.While cyclic charging/discharging was performed at 0.1,0.2,0.5,1.0 and 0.1 A/g current densities,the specific discharge capacities were 102.3,96.0,91.4,85.6 and 96.5 mAh/g,respectively,showd good rate performance.Compared with pristine Na_(3)V_(2)(PO_(4))_(2)F_(3),the capacity was increased by about 20%.
作者
陈仟惠
卢秋影
李仁才
欧盈君
黄蔚欣
李华锋
龚福忠
CHEN Qianhui;LU Qiuying;LI Rencai;OU Yingjun;HUANG Weixin;LI Huafeng;GONG Fuzhong(College of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China;Guangxi Chemical Research Institute Co.,Ltd.,Nanning 530001,China;Guangxi Huana New Material Co.,Ltd.,Nanning 530103,China)
出处
《化工技术与开发》
CAS
2024年第9期37-41,共5页
Technology & Development of Chemical Industry
