摘要
分别制备硫碳比为6∶4、7∶3、8∶2、9∶1的Li-S电池正极材料。采用XRD分析了这4种正极材料的成分结构,用场发射扫描电子显微镜观察了它们的形貌,利用交流阻抗谱、循环伏安和电池充放电测试电池的电化学性能。结果表明:正极材料S∶C=8∶2时,电池在0.2 C放电倍率下,首次放电容量为1299 m Ah/g,100次循环后仍能保持570 m Ah/g左右,经过20次循环后电池的库仑效率仍稳定在99%左右,性能明显优于其他3种正极材料组成的电池。
Anode materials of lithium-sulfur batteries are synthesized by heating element sulfur with porous carbon at the proportion of 6： 4, 7： 3, 8：2 and 9： 1. Morphologies and structures of the sulfur-carbon materials are determined by field emission scanning electron microscope （FES- EM） and XRD. Electrochemical properties are characterized by electrochemical impedance spectros- copy, cyclic voltammetry, and charge-discharge. The results show that the battery assembled by the composite of porous carbon and sulfur at the proportion of 8：2 exhibits better properties than the others, and its initial discharge capacity is up to 1299 mA.h/g at a discharge rate of 0.2 C and maintain about 570 mA.h/g after 100 cycles. The coulombic efficiency of it is about 99% after 20 cycles at a discharge rate of 0.2 C.
出处
《电工材料》
CAS
2016年第6期3-7,共5页
Electrical Engineering Materials
关键词
Li-S电池
升华硫
多孔碳
放电量
循环特性
库仑效率
lithium-sulfur battery
sublimed sulfur
porous carbon
discharge capacity
cycle perfor- mance
coulombic efficiency
