Electrochemical Properties of Lithium–Sulfur Cells in a Very Wide Range of Sulfur Concentration

Bulletin of the Korean Chemical Society

Yongju Jung¹  Jeong Yoon Koh¹  Hye Jeong Yang²  Tae Jeong Kim² 

[1] 708 Republic of Korea;Department of Chemical Engineering Korea University of Technology and Education (KOREATECH) Cheonan 330‐

关键词: Li–;    S cells;    Sulfur concentration;    Sulfur utilization;    Rate property;    Cycle performance;   

DOI  :  10.1002/bkcs.10643

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

This paper examines the influence of the sulfur concentration on the electrochemical properties of Li–S cells over a very wide sulfur concentration range of 1.5 to 14.2 m. The sulfur utilization decreased gradually from 74 to 40% with increasing sulfur concentration in this concentration range. Surprisingly, the Li–S cells successfully operated with a considerable capacity (675 mAh/g) even under an extremely high sulfur concentration of 14.2 m. At a high rate of 5.0 C, the cells with 9.8 and 11.5 m sulfur showed much poorer rate capabilities than those with 2.3 and 5.6 m sulfur. This feature was attributed mainly to the significant ohmic drop and large reaction overpotential due to chemical reactions coupled with the electrode reactions of sulfur and polysulfides. In addition, there was a notable variation in the cycle performance with a change in the sulfur concentration. Interestingly, higher capacity retention was observed in 5.6 and 9.8 m sulfur than in low (2.3 m) and high (11.5 m) sulfur concentrations.

【 授权许可】

Unknown