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以LiOH.H2O、V2O5、H3PO4和蔗糖为原料,采用软化学法制备了锂离子电池正极材料Li3V2(PO4)3/C。通过X射线衍射(XRD)、扫描电镜(SEM)对产物的结构和形貌进行表征,采用恒电流充放电、电化学阻抗考察了产物的电化学性能。结果表明,当煅烧温度达到700℃时,杂质相衍射峰消失,所得的样品为纯相的单斜Li3V2(PO4)3,颗粒粒度为1~2μm;在3.0~4.5 V电压范围内以0.2C倍率充放电,首次放电比容量达到148.2 mAh.g-1,第50次循环比容量仍为144 mAh.g-1,容量保持率为97%,具有良好的循环性能;另外,样品还具有很好的倍率性能和高温性能。
Li3V2 (PO4) 3 / C was prepared by soft chemical method using LiOH.H2O, V2O5, H3PO4 and sucrose as raw materials. The structure and morphology of the product were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical properties of the product were investigated by galvanostatic charge-discharge and electrochemical impedance spectroscopy. The results show that when the calcination temperature reaches 700 ℃, the diffraction peak of the impurity phase disappears. The obtained sample is pure monoclinic Li3V2 (PO4) 3 with particle size of 1 ~ 2μm. With the voltage range of 3.0 ~ 4.5V, The first discharge capacity reached 148.2 mAh.g-1, the specific capacity of the 50th cycle was still 144 mAh.g-1, the capacity retention rate was 97%, with good cycle performance; in addition, the sample also has a very good Good rate performance and high temperature performance.