Ni2+掺杂对Li3V2(PO4)3电化学性能的影响
来源期刊：中国有色金属学报2012年第11期
论文作者：鲁道荣 胡德鹏 刘兴亮
文章页码：3144 - 3150
关键词：锂离子电池；Ni2+；Li3V2(PO4)3；掺杂；电化学性能
Key words：Li-ion battery; Ni2+; Li3V2(PO4)3; doping; electrochemical performance
摘 要：采用X射线衍射(XRD)、透射电镜(TEM)和电化学方法，研究Ni2+掺杂对正极材料Li3V2(PO4)3的结构、形貌和电化学性能的影响。结果表明：掺杂适量的Ni2+不会改变Li3V2(PO4)3的单斜晶系结构，但可提高材料的电导率，抑制电池在充放电过程的极化。在室温下，Li3(Ni0.05V0.95)2(PO4)3以0.1C倍率放电的初始比容量为115 mA·h/g，放电倍率从0.1C增加到0.4C循环60次后，比容量衰减率仅为2.7%，而未掺杂原样Li3V2(PO4)3的初始比容量为129 mA·h/g，60次循环后比容量衰减率约为30.3%；当放电倍率增至1C时，80次循环后，Li3(Ni0.05V0.95)2(PO4)3比容量为99.8 mA·h/g，而原样的比容量为84.1 mA·h/g；当放电倍率增至5C时，循环120次后，Li3(Ni0.05V0.95)2(PO4)3比容量为67.7 mA·h/g，而原样的比容量降为0。循环伏安和交流阻抗测试表明，Li3(Ni0.05V0.95)2(PO4)3的可逆性明显优于Li3V2(PO4)3的可逆性。
Abstract: The effects of Ni2+ doping on the structure, morphology and electrochemical performance of cathode material Li3V2(PO4)3 were studied by X-ray diffractometry(XRD), transmission electron microscopy(TEM) and electrochemical method. The results indicate that the monoclinic structure of Li3V2(PO4)3 is not changed while the conductivity increases and the polarization of the battery is restrained during charge-discharge process due to doping appropriate amount of Ni2+. Li3(Ni0.05V0.95)2(PO4)3 has an initial specific capacity of 115 mA·h/g at 0.1C discharging at room temperature and the specific capacity only decreases by 2.7% after 60 cycles when the discharging rate changes from 0.1C to 0.4C. However, the raw sample Li3V2(PO4)3 has an initial specific capacity of 129 mA·h/g and the specific capacity decreases by 30.3% after 60 cycles. Furthermore, when the discharging rate increases to 1C, the specific capacity of Li3(Ni0.05- V0.95)2(PO4)3 decrease slightly to 99.8 mA·h/g after 80 cycles, while the specific capacity of the raw sample declines considerably to 84.1 mA·h/g. When the discharging rate increases to 5C, the specific capacity of Li3(Ni0.05V0.95)2(PO4)3 decreases to 67.7 mA·h/g after 120 cycles, while the specific capacity of the raw sample declines to 0. Additionally, the tests of cyclic voltammogram and AC impedance show that the reversibility of Li3(Ni0.05V0.95)2(PO4)3 is obviously better than that of Li3V2(PO4)3.
鲁道荣1, 2，胡德鹏1，刘兴亮1
(1. 合肥工业大学 化工学院，合肥 230009；
2. 可控化学与材料化工安徽省重点实验室，合肥 230009)
摘 要：采用X射线衍射(XRD)、透射电镜(TEM)和电化学方法，研究Ni2+掺杂对正极材料Li3V2(PO4)3的结构、形貌和电化学性能的影响。结果表明：掺杂适量的Ni2+不会改变Li3V2(PO4)3的单斜晶系结构，但可提高材料的电导率，抑制电池在充放电过程的极化。在室温下，Li3(Ni0.05V0.95)2(PO4)3以0.1C倍率放电的初始比容量为115 mA·h/g，放电倍率从0.1C增加到0.4C循环60次后，比容量衰减率仅为2.7%，而未掺杂原样Li3V2(PO4)3的初始比容量为129 mA·h/g，60次循环后比容量衰减率约为30.3%；当放电倍率增至1C时，80次循环后，Li3(Ni0.05V0.95)2(PO4)3比容量为99.8 mA·h/g，而原样的比容量为84.1 mA·h/g；当放电倍率增至5C时，循环120次后，Li3(Ni0.05V0.95)2(PO4)3比容量为67.7 mA·h/g，而原样的比容量降为0。循环伏安和交流阻抗测试表明，Li3(Ni0.05V0.95)2(PO4)3的可逆性明显优于Li3V2(PO4)3的可逆性。
关键词：锂离子电池；Ni2+；Li3V2(PO4)3；掺杂；电化学性能
LU Dao-rong1, 2, HU De-peng1, LIU Xing-liang1
(1. School of Chemical Engineering, Hefei University of Technology, Hefei 230009, China;
2. Anhui Key Laboratory of Controllable Chemical Reaction & Material Chemical Engineering,
Abstract:The effects of Ni2+ doping on the structure, morphology and electrochemical performance of cathode material Li3V2(PO4)3 were studied by X-ray diffractometry(XRD), transmission electron microscopy(TEM) and electrochemical method. The results indicate that the monoclinic structure of Li3V2(PO4)3 is not changed while the conductivity increases and the polarization of the battery is restrained during charge-discharge process due to doping appropriate amount of Ni2+. Li3(Ni0.05V0.95)2(PO4)3 has an initial specific capacity of 115 mA·h/g at 0.1C discharging at room temperature and the specific capacity only decreases by 2.7% after 60 cycles when the discharging rate changes from 0.1C to 0.4C. However, the raw sample Li3V2(PO4)3 has an initial specific capacity of 129 mA·h/g and the specific capacity decreases by 30.3% after 60 cycles. Furthermore, when the discharging rate increases to 1C, the specific capacity of Li3(Ni0.05- V0.95)2(PO4)3 decrease slightly to 99.8 mA·h/g after 80 cycles, while the specific capacity of the raw sample declines considerably to 84.1 mA·h/g. When the discharging rate increases to 5C, the specific capacity of Li3(Ni0.05V0.95)2(PO4)3 decreases to 67.7 mA·h/g after 120 cycles, while the specific capacity of the raw sample declines to 0. Additionally, the tests of cyclic voltammogram and AC impedance show that the reversibility of Li3(Ni0.05V0.95)2(PO4)3 is obviously better than that of Li3V2(PO4)3.
Key words:Li-ion battery; Ni2+; Li3V2(PO4)3; doping; electrochemical performance
