纳米SnO2-SiO2复合氧化物的制备与电化学性能

Preparation and electrochemical performance of nano- SnO_2-SiO_2 composites

以SnCl2·5H2O和Si(OMe)4为原料,通过尿素控制反应的pH值,采用水热法制备出了细小的SnOy-SiO2复合物,使活性物质SnOy很好地分散于非活性相物质SiO2中,保持活性成分在原子或纳米尺度上均匀分散于非活性基质成分中。纳米SnO2-SiO2复合物作为锂离子电池负极材料,其首次放电容量达到1208mAh/g,首次可逆容量为756mAh/g,首次库仑效率达到62.6%,随后的库仑效率都保持在90%以上,20次内每次循环的容量衰减率只有0.9%。纳米SnO2-SiO2复合物电极具有较好的循环嵌脱锂性能,是有希望的锂离子电池负极材料。

Nano-SnO2-SiO2composites were prepared by a modified hydrothermal method, using SnCl2 and equal amounts of Si（OMe）4 as the starting materials and CO（NH2）2 as PH regulator.Fine powders of tin oxide as active materials were doped with highly dispersed silicon oxide as inert materials in atomic or nano-meter scale. Nano-SnO2-SiO2 composites as anode materials were achieved a initial discharge capacity of 1 208 mAh·g^-1 and a charge capacity of 756 mAh/g, a coulombic efficiency was more than 90% except for the first cycle （62.6%）, and the capacity loss per cycle is about 0.9% after 20 cycles which suggests that tin oxide-based materials work as high capacity anodes for lithium-ion rechargeable batteries.