摘 要: 使用还原铁粉作为铁源, 通过超细球磨与喷雾干燥、高温煅烧技术制备了球形微纳米 LiFePO 4 /C 复合材料。 使用 DSC/TG 以及 XRD 对 LiFePO 4 /C 复合材料的形成过程进行了分析; 使用 SEM、 穆斯堡谱仪等手段对复合材料 进行分析; 使用电化学工作站、容量测试仪对其充放电行为进行分析。研究发现, 使用该合成技术路线, 在 500~700℃下能够合成 LiFePO 4 /C 复合材料。获得的 LiFePO 4 /C 复合材料具有规则的球形外貌, 平均尺寸 4~5 μm。 该微米颗粒由 200 nm 左右细小颗粒组成, 颗粒间具有纳米尺寸微孔。穆斯堡谱仪测试结果表明, 复合材料中 Fe 处 于+2 价的价态。复合材料在 1C 倍率下表现出稳定的充放电行为, 平均比容量在 156 mAh/g, 300 次循环后, 容量保 持率为 92.8%。该技术制备的 LiFePO 4 /C 复合材料具有潜在的应用价值。 Abstract: Using Fe source as starting material, the composite LiFePO 4

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... material was obtained through a combined method of nano grinding, spray drying and high temperature calcinating. The as-prepared samples were verified by TG/DSC and XRD and characterized by SEM and Mossbauer spectrum. The electrochemical performances were studied by CV and cyclic tests. The results show that the LiFePO 4 /C composite is successfully synthesized by calcinating the precursor at 500-700 . ℃ The obtained LiFePO 4 /C materials are spherical porous agglomerates with mean size of 4-5 μm, which are composed of 200 nm particles. According to Mössbauer data, all the iron ions are in +2 valence state. The spherical nano LiFePO 4 /C composite shows great electrochemical performance as potential cathode material for lithium ion batteries, with a specific capacity of 156 mAh/g at 1C rate and capacity retention of 92.8% after 300 charge/discharge cycles.