Study on surface coating modification of silicon anode material with titanium dioxide
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摘要: 以TiCl4为钛源,商用纳米Si为硅源,采用水解法制备了核—壳结构的硅@二氧化钛(Si@TiO2)纳米复合材料。借助XRD、SEM、TEM和电化学性能测试等对材料进行了详细研究。结果显示,坚固的TiO2外壳在充放电过程中极大缓解了硅的体积膨胀,使得Si@TiO2展现出较好的电化学性能,其在1600 mAh/g大电流密度下的放电比容量为614.3 mAh/g。电流密度500 mA/g,循环100次后仍有877 mAh/g的放电比容量,容量保持率为51.8%。Abstract: Titanium dioxide coated silicon (Si@TiO2) nanocomposites with core-shell structure was prepared by hydrolysis method using TiCl4 as titanium source and commercial nano-Si as silicon source. The materials were characterized and tested by XRD, SEM, TEM and electrochemical platform. The results show that Si@TiO2 nanocomposites exhibit good electrochemical performance because the solid TiO2 shell greatly alleviates the volume expansion of silicon during the charging and discharging process (showing a discharge specific capacity is of 614.3 mAh/g at a high current density of 1600 mAh/g and a specific discharge capacity of 877 mAh/g with a capacity retention rate of 51.8% after 100 cycles at a current density of 500 mAh/g).
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Key words:
- Si@TiO2 nanocomposite /
- hydrolysis /
- TiCl4 /
- silicon /
- negative electrode /
- electrochemical performance
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表 1 不同钛源制备的硅基复合材料储锂性能比较
Table 1. Comparison of lithium storage performance of composite materials prepared from different titanium sources
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