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以离子液体1-丁基-3甲基咪唑二腈胺盐为碳源,通过微波辅助加热法制备LiFePO_4/C正极材料。采用X射线衍射(XRD)表征了样品的物相,扫描电镜(SEM),透射电镜(TEM)考察了样品的微观形貌,元素分析检测了离子液体最终产物中C、H、N元素的含量。通过恒电流充放电测试研究了材料的电化学性能,主要研究了加热方式和Mg2+掺杂对材料性能的影响。结果表明,微波加热可以高效快速制备LiFePO_4/C,有利于离子液体碳化形成碳层。在加热时间较长的情况下,会造成颗粒的不规则长大。Mg2+的掺杂不会改变LiFePO_4/C颗粒的形貌,0.1C倍率下首次放电比容量达到146.3mAh/g,经过45次循环后容量没有明显衰减,可以有效地改善LiFePO_4/C的电化学性能。
LiFePO 4 / C cathode material was prepared by microwave-assisted heating method using 1-butyl-3-methylimidazolium dinitrile as ionic source. The microstructure of the sample was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The content of C, H and N in the final product of ionic liquid . The electrochemical performance of the material was investigated by galvanostatic charge-discharge test. The effects of heating method and Mg2 + doping on the properties of the material were studied. The results show that microwave heating can efficiently and rapidly prepare LiFePO 4 / C, which is good for carbonation of ionic liquid to form carbon layer. In the case of a longer heating time, will cause irregular growth of particles. The doping of Mg2 + does not change the morphology of LiFePO4 / C particles. The initial discharge capacity of LiFePO4 / C particles reaches 146.3mAh / g at 0.1C rate, and the capacity of LiFePO4 / C can be effectively improved after 45 cycles .