| Li3V2(PO4)3/C和Li2.5Na0.5V2(PO4)3/C的结构和电化学性能的比较研究(英文) |
| A Comparative Structural and Electrochemical Study of Monoclinic Li3V2(PO4)3/C and Rhombohedral Li2.5Na0.5V2(PO4)3/C |
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| 摘要: 采用溶胶-凝胶法合成了锂离子正极材料Li3V2(PO4)3/C(LVP/C)及Li2.5Na0.5V2(PO4)3/C，并用XRD、循环伏安及交流阻抗等方法，研究了大量Na+掺杂对材料结构和电化学性能影响。结果表明，大量钠离子的掺杂会使LVP结构由单斜向菱方转变。掺杂化合物Li2.5Na0.5V2(PO4)3/C在0.5 C充电1 C放电时，首次放电容量为118 mAh·g-1，50次循环后容量保持率为92.4%，并发现与单斜LVP存在多个放电平台不同，Li2.5Na0.5V2(PO4)3/C仅在3.7 V处有一个放电平台。 |
| 关键词: 锂离子电池 正极材料 磷酸钒锂 溶胶凝胶法 钠掺杂 晶体结构 |
| 基金项目: |
| Abstract: A lithium-ion battery cathode material, Li2.5Na0.5V2(PO4)3/C, was prepared by the sol-gel method and characterized by X-ray diffraction (XRD), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). As a control, Li3V2(PO4)3/C(LVP/C) was also prepared and studied. The effect of sodium-ion doping on the structure and electrochemical properties was studied. The XRD pattern of Li2.5Na0.5V2(PO4)3/C indicates that the monoclinic structure of Li3-xNaxV2(PO4)3 has transformed into a rhombohedral structure because of large amount of sodium-ion doping. For Li2.5Na0.5V2(PO4)3/C, a specific discharge capacity of 118 mAh·g-1 is achieved at a 0.5 C charge rate and 1 C discharge rate, and a 92.4% retention rate of the initial capacity is obtained after 50 cycles. Different from monoclinic LVP, there is only one discharge plateau at 3.7 V in the charge/discharge voltage profile of Li2.5Na0.5V2(PO4)3/C. |
| Keywords: lithium-ion battery cathode material lithium vanadium phosphate sol-gel preparation Na-doping crystal structure |
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| 王文辉,陈振宇,戴长松,纪大龙,李佳杰,魏 杰.Li3V2(PO4)3/C和Li2.5Na0.5V2(PO4)3/C的结构和电化学性能的比较研究(英文)[J].无机化学学报,2012,28(5):1070-1074. |
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