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采用鳞片石墨、纳米硅及水合葡萄糖为原料,通过液相固化及高温热解法制备了硅/碳复合材料.采用X射线衍射光谱法(XRD)、扫描电子显微镜法(SEM)、透射电子显微镜法(TEM)及电化学测试表征了该材料的结构及性能.实验结果表明:这种复合材料由纳米硅颗粒、鳞片石墨及热解无定形碳组成,在无定形碳的包覆网络中,纳米硅颗粒分布在石墨片层上.该材料首次充电容量为733.6 mAh·g-1,首次库伦效率为69.98%,经20次循环后其容量保持率为80.01%,而纯纳米硅电极的容量保持率只有15.21%.在不同的电流密度下,该复合材料也展现了良好的电极循环性能,电化学性能的改善被认为是该材料的特殊结构以及碳包覆的结果.
Silicon / carbon composites were prepared by using flake graphite, nanosilica and hydrated glucose as raw materials and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy The structure and properties of the composites were characterized by TEM and electrochemical measurements.The experimental results show that the composites consist of nano-silicon particles, flake graphite and pyrolytic amorphous carbon, The nanosilica particles distributed on the graphite layer.The first charge capacity of the material was 733.6 mAh · g-1, the first coulombic efficiency was 69.98%, the capacity retention rate was 80.01% after 20 cycles, while the capacity of pure nanosilica electrode The retention rate was only 15.21% .At the same time, the composites also exhibited good electrode cycling performance. The improvement of electrochemical performance was considered as a result of the special structure of the material and the carbon coating.