二氧化钛用于硅负极材料表面包覆改性的研究

Study on surface coating modification of silicon anode material with titanium dioxide

以TiCl_(4)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@TiO_(2))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TiO_(2)外壳在充放电过程中极大缓解了硅的体积膨胀,使得Si@TiO_(2)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%。

Titanium dioxide coated silicon(Si@TiO_(2))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@TiO_(2)nanocomposites exhibit good electrochemical performance because the solid TiO_(2)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).