深冷处理温度对锡锑/碳纳米纤维负极材料锂电性能的影响

Influence of deep cryogenic treatment temperature on lithium electrical properties of SnSb/C nanofiber anode material

为提高锡锑/碳(SnSb/C)纳米纤维作为负极材料的锂电池的循环使用性能,利用深冷处理对SnSb/C纳米纤维进行形貌再造,比较不同深冷温度处理前后纳米纤维的形貌变化,并测试其含碳量和比表面积,通过分析电池的恒流充放电曲线研究深冷处理温度的变化对其电化学性能的影响。结果表明:当深冷处理温度为-100℃时,SnSb/C纳米纤维表面粗糙度增加并出现沟壑;深冷处理加快了聚丙烯腈的预氧化反应速度,使其分解温度提前,含碳量高达75. 4%,比表面积为214. 0 m^2/g;锂电循环过程中,因深冷处理对其形貌结构的影响,电池容量呈持续上升趋势,循环120圈后容量保持率为123. 5%。

In order to improve the electrochemical performance of SnSb/C nanofibers anodes for lithium-ion battery,the deep cryogenic treatment was used to modify the morphology of SnSb/C nanofibers,the influence of cryogenic temperature on the electrochemical performance was studied by comparing the changes of morphology,the specific surface area,the carbon contents and the charge-discharge curve of SnSb/C nanofibers.The results show that when the cryogenic temperature is -100 ℃,SnSb/C nanofiber has a rough surface with gullies.The cryogenic treatment accelerates the preoxidation reaction speed of polyacrylonitrile,so that the decomposition temperature decrease,the carbon content is up to 75.4% and the specific surface increases to 214.0 m 2/g.Besides,owing to the influence of deep cryogenic treatment on the morphology of SnSb/C nanofibers,the battery capacity sustainably increases during the cycling of the lithium ion battery.After 120 cycles,the capacity retention ratio is still 123.5%.