关键词: 正极材料, 喷雾干燥, 辅助模板, PVA

Abstract: In this work, the LiFePO4/C composites were prepared by the spray drying and carbothermal method, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The effects of the organic assisted templates on the morphologies and electrochemical properties of the LiFePO4/C composites were investigated. The results showed that the morphology and microstructure of the composites could be tuned by incorporating with the different templates. The morphology of the composite appeared to be solid microspheres if no organic template was added, while porous microspheres, nest-like aggregation, and uniform nano-micro spheres, if citric acid, glucose, and PVA were used as the templates, respectively. Among all the samples, the composite prepared with PVA as a template also exhibited the best properties in batteries, including the highest tap density, the lowest charge transfer resistances and the highest capacities. The best discharge capacities were measured to be 156.7 and 92.1 mAh?g–1 at 0.1 and 5.0 C rate, respectively. The obvious charge-discharge plateaus at high rates and excellent cycling performance at various rates were achieved.

Key words: cathode materials, spray drying, assisted template, PVA