以CH3COOLi·2H2O、V2O5、Mn(CH3COO)2·4H2O、(NH4)2HPO4和蔗糖为原料, 采用溶胶–凝胶法合成了掺锰磷酸钒锂/碳(Li3V2-2x/3Mnx(PO4)3/C)复合正极材料, 用XRD、XPS、SEM、电化学性能对样品进行了表征. 测试结果表明, 少量锰的掺杂并未改变Li3V2(PO4)3/C的单斜结构, Li3V1.94Mn0.09(PO4)3中的Mn和V分别以+2和+3价存在, 其颗粒类似球形, 直径比较均匀且小于200 nm, 并表现出良好的电化学性能. 在0.1C倍率和3.0~4.8 V电压内, 该样品的首次充、放电容量分别为182.1和168.8 mAh/g, 放电效率高达92.69%, 而且100次循环后, 其放电比容量仍是首次放电容量的77.4%.
Novel cathode material Li3V2-2x/3Mnx(PO4)3/C was successfully synthesized by Sol-Gel method using CH3COOLi·2H2O, V2O5, Mn(CH3COO)2·4H2O, (NH4)2HPO4 and sucrose as raw materials. The as-prepared products were characterized by XRD, XPS, SEM.The results show that a small amount of Mn2+doping do not alter the structure of Li3V2(PO4)3 materials with a monoclinic structure (space group P21/n), and the valence states of V and Mn in Li3V1.94Mn0.09(PO4)3/C are +3 and +2, respectively. The Li3V1.94Mn0.09(PO4)3 particle with uniform shape of sphere and diameter less than 200 nm, shows the best cyclic stability and rate performance. Controlling the charge and discharge voltage range from 3.0 to 4.8 V at the rate of 0.1C, the first charge and discharge capacity of Li3V1.94Mn0.09(PO4)3 are up to 182.1 and 168.8 mAh/g, respectively, and its discharge efficiency is up to 92.69%. After 100 cycles, its discharge capacity can also retain 77.4% of the first one.
参考文献
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| [4] | 刘素琴, 李世彩, 唐联兴, 等(LIU Su-Qing, et al)．Li3V2(PO4)3的溶胶&ndash |
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