C/TiO2包覆SiO2用作锂离子电池负极材料

C/TiO2 coated SiO2 as anode material for lithium ion batteries

以多孔SiO2为内核,利用TiO2与碳外层包覆制备出双壳结构(SiO2@TiO2@C)作为锂离子电池的负极材料。TiO2纳米粒子均匀地嵌入具有多孔的SiO2粒子内部和表面,形成SiO2@TiO2核-壳结构。碳包覆形成的外壳可以很好地避免SiO2与电解质直接接触,因此形成稳定的SEI膜。得到的SiO2@TiO2@C核-壳-壳材料具有疏松的多孔结构、高比容量、优异的倍率性能和稳定的长期循环性能。比表面积和总孔隙率分别为261.3 m^2/g和0.46 cm^3/g,在电流密度为0.1 A/g时,首次库仑效率为74.7%,100次循环后的放电比容量为638 mAh/g,容量保持率大于98.5%。这些结果表明所得到的复合材料有很好的前景,在改进各种储能材料方面可能具有潜在的应用。

Dual core shell structure as the anode material of lithium ion batteries(SiO2@TiO2@C)was prepared using porous SiO2 as the core with TiO2 and carbon outer coating.TiO2 nanoparticles were uniformly embedded in and on the surface of porous SiO2 particles to form SiO2@TiO2 core-shell structure.The shell formed by carbon can avoid direct contact between SiO2 and electrolyte and form stable SEI film.The obtained SiO2@TiO2@C core-shell-shell particles have porous structure,high specific capacity,excellent rate performance and stable long-term cycling performance.The specific surface area and pore volume were 261.3 m^2/g and 0.46 cm^3/g,respectively.The first coulomb efficiency is 74.7%at the current density of 0.1 A/g,and a stable specifc capacity of 638 mAh/g is achieved after 100 cycles(retention 98.5%).These results indicate that the obtained composite materials have great prospects and may have potential applications in improving various energy storage materials.