用共沉淀法合成Fe0.97Mn0.03 PO4前驱体, 再通过碳热还原法合成多元掺杂的Li0.97+δTi0.03Fe0.97Mn0.03 PO4/C复合材料, 利用X射线衍射(XRD)、扫描电镜(SEM)、傅立叶红外光谱(FTIR)等测试手段对样品的晶体结构、表观形貌、谱学性质等进行了分析研究, 对其倍率
放电性能及循环性能等进行了测试, 并与不掺杂的LiFePO4/C复合材料进行了比较. 研究表明, 掺杂过程中, 掺杂的Mn4+、Ti4+离子能与LiFePO4形成单一的橄榄石型晶体结构, 晶型完整, 产物形貌规则, 平均粒径在1μm左右. 用Li0.97+δTi0.03Fe0.97Mn0.03 PO4/C
为正极材料制作的电池分别以0.2、1、5、10C倍率放电, 首次放电容量为134.0、133.4、130.1和127.2mAh·g-1, 并表现出良好的循环性能.
The composite cathode material of Li0.97+δTi0.03Fe0.97Mn0.03 PO4/C was synthesized by carbothermal reduction of FeFe0.97Mn0.03 PO4 which was prepared by co-precipitation method. The samples were characterized by X-ray diffraction, scanning electron microscope, FTIR absorption spectra, and their electrochemical performances were investigated in terms of rate discharge and cycling behavior. The results show that Li0.97+δTi0.03Fe0.97Mn0.03 samples are simple pure olive-type phase, and the particles are homogeneous with average particle size of about 1μm. The ion dopants of Mn4+ and Ti4+ do not affect the structure of the material. Compared with LiFePO4/C, the composite compound Li0.97+δTi0.03Fe0.97Mn0.03 exhibits good electrode properties with discharge capacities of 134.0, 133.4, 130.1 and 127.2mAh·g-1 at 0.2, 1, 5 and 10C rates, respectively. In addition, it shows excellent cycle stability at different rates.
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