摘要
作为一种储量丰富的农业废弃物,稻壳的高附加值利用具有重要意义。以稻壳为原料,通过空气氧化、镁热还原和酸浸得到硅/碳复合材料,探讨了复合材料的组成结构以及作为锂离子电池负极材料的电化学性能。结果表明:硅/碳复合材料中的硅为晶体纳米颗粒,分布在无定形炭基质中;稻壳的氧化增加了硅/碳复合材料中硅的含量和复合材料的比表面积,从而增加了复合材料的容量,但首次库伦效率较低;硅/碳复合材料中的碳可以抑制硅的体积变化,改善循环性能。含碳8%的硅/碳复合材料,首次充电容量758.5mAh/g,30次循环后充电容量保持率为78.7%。
Rice husk is an abundant agricultural waste and its high value-added application is of great worth. Through magnesiothermic reduction of the oxidized rice husks and acid-leaching of the reduction products, Si/C composites were synthesized, and the composition, structure and electrochemical performance of them as anode materials for lithium-ion batteries, were explored. The results show that： Silicon in the Si/C composites is crystalline silicon nanoparticles distributed in amorphous carbon matrix; Si content and the special surface area of the as synthesized Si/ C composites increase with the oxidization of rice husks, and hence the capacity increases, but all composites having low first coulombic efficiencies; the volume change of silicon in the as synthesized Si/C composites can be refrained by carbon, thus improving their cycling performance. Si/C composite with carbon content of 8. 0% had the first charge capacity of 758. 5 mAh/g, and retained 78.7% after 30 cycles.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2015年第22期43-47,共5页
Materials Reports
基金
国家自然科学基金(51264016)
云南省自然科学基金(2014FA025)
昆明理工大学分析测试基金(20150265)
关键词
稻壳
镁热还原
硅/碳复合材料
电化学性能
rice husks, magnesiothermic reduction, silicon/carbon composite, electrochemical performance
