不同微波时间的硫/膨胀石墨阴极材料锂硫电池性能研究

Research on the Sulfur/Expanded Graphite Cathode for Lithium-sulfur Batteries with Different Microwave Time

随着高科技电子产品的不断发展,电池扮演着越来越重要的角色,同时,人们也越来越注重电池的性能。由于锂离子电池理论比容量有限,难以满足目前对更高能量密度的需求,而硫电极理论比容量可高达1 675mAh/g,以硫与金属锂构建的锂/硫二次电池体系的理论能量密度达2 600 Wh/kg,远大于现阶段所使用的商业化二次电池。采用微波法成功制备了硫/膨胀石墨复合材料,通过控制微波时间可实现对硫含量的控制。对材料进行了扫描电镜、热重和X射线衍射等研究,结果表明,复合材料中确实存在硫,且在同一比例时,随着微波时间的延长,硫含量逐渐减少。电化学研究结果表明,在0.5 min时,材料具有最好的电化学性能,首次放电容量达650mAh/g。

With the coming out of high-tech electronic products,batteries have been playing an increasingly important role,at the same time,people are increasingly focused on battery performance.Due to the theoretical specific capacity is limited,lithium-ion batteries is difficult to meet today＇s demand for higher energy density.The sulfur electrode theoretical specific capacity of up to 1 675mAh/g,lithium/sulfur battery system which is consisted of sulfur and metal lithium theoretical energy density is 2 600Wh/kg,much larger than the commercialized secondary batteries now.In the paper,successfully prepared the sulfur/expanded graphite,and could control the load of sulfur by controlling the microwave time.A series of studies by SEM、TG、XRD for composites showed that the sulfur dose exist in the composites,and the load decreased following the adding of microwave time at the same ratio.The electrochemical results showed that the composites with 30 smicrowave time have best electrochemical performances,the first discharge capacity is 650mAh/g.