Synthesis and characterization of electrochemically active graphite–silicon–tin composite anodes for Li-ion applications
Synthesis and characterization of electrochemically active graphite–silicon–tin composite anodes for Li-ion applications
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DOI：
10.1016/j.jpowsour.2006.10.068
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发表时间：
2007-02
影响因子：
9.2
通讯作者：
Nicolaus L. Rock;P. Kumta
中科院分区：
文献类型：
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作者：
Nicolaus L. Rock;P. Kumta
采用干湿高能机械铣削（HEMM）制备了分散在碳（石墨）基体上的具有电化学活性的Si0.66Sn0.34（SiSn）复合合金。经x射线衍射（XRD）验证，所得复合材料由非晶碳（干燥HEMM的情况下）或结晶碳（湿HEMM的情况下）以及晶体硅和锡（两种情况下）组成。XRD结果还表明，在干燥HEMM过程中，铁锡金属间化合物（FeSn2）作为污染物产生。85C-15 [Si0.66Sn0.34] （mol%）复合材料的可逆放电容量高达800mAhg−1，且容量保持合理（1.36%损耗/循环）。扫描电镜（SEM）和傅里叶变换红外光谱（FTIR）分析进一步检查了电极表面，并分别确定电极，锂离子和电解质之间反应产生的有机物质的存在/不存在。
Electrochemically active Si0.66Sn0.34(SiSn) composite alloys dispersed in a carbon (graphite) matrix were synthesized using both wet and dry high-energy mechanical milling (HEMM). The resultant composites are comprised of amorphous carbon (in the case of dry HEMM) or crystalline carbon (in the case of wet HEMM), and crystalline silicon and tin (for both cases) as verified by X-ray diffraction (XRD). The XRD results also indicate the presence of iron–tin intermetallic (FeSn2) arising as a contaminant during dry HEMM. The composite composition of 85C–15[Si0.66Sn0.34] (mol%) resulted in reversible discharge capacities as high as 800mAhg−1with a reasonable capacity retention (1.36% loss/cycle). Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses were further conducted to examine the surface of the electrode and to determine the presence/absence of organic species resulting from reactions between the electrode, lithium ions and electrolyte, respectively.