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基于富缺陷结构的单原子催化剂在Li-S电池领域应用的研究论文在Small发表
发布者: 谭强 | 2022-11-29 | 655

近日,课题组基于富缺陷结构的单原子催化剂在Li-S电池领域应用的研究论文“Defect-Rich Single Atom Catalyst Enhanced Polysulfide Conversion Kinetics to Upgrade Performance of Li–S Batteries”在材料学科知名期刊《Small》上发表。已毕业的井伟涛博士是论文的第一作者,段玉娥硕士为本文的催化剂制备和结构分析提供了帮助。

 

 

https://doi.org/10.1002/smll.202204880

 

Abstract: 

Lithium–sulfur (Li–S) batteries have attracted considerable attention owing to their extremely high energy densities. However, the application of Li–S batteries has been limited by low sulfur utilization, poor cycle stability, and low rate capability. Accelerating the rapid transformation of polysulfides is an effective approach for addressing these obstacles. In this study, a defect-rich single-atom catalytic material (Fe-N4/DCS) is designed. The abundantly defective environment is favorable for the uniform dispersion and stable existence of single-atom Fe, which not only improves the utilization of single-atom Fe but also efficiently adsorbs polysulfides and catalyzes the rapid transformation of polysulfides. To fully exploit the catalytic activity, catalytic materials are used to modify the routine separator (Fe-N4/DCS/PP). Density functional theory and in situ Raman spectroscopy are used to demonstrate that Fe-N4/DCS can effectively inhibit the shuttling of polysulfides and accelerate the redox reaction. Consequently, the Li–S battery with the modified separator achieves an ultralong cycle life (a capacity decay rate of only 0.03% per cycle at a current of 2 C after 800 cycles), and an excellent rate capability (894 mAh g−1 at 3 C). Even at a high sulfur loading of 5.51 mg cm−2 at 0.2 C, the reversible areal capacity still reaches 5.4 mAh cm−2.

 

单原子催化剂形貌和结构表征

催化剂元素分布和活性位点配位结构表征

 

富缺陷单原子催化剂对多硫化物的阻挡作用表征

 

富缺陷单原子催化剂对多硫化物的阻挡作用的理论计算

 

基于富缺陷结构单原子催化剂的Li-S电池电化学性能测试

充放电过程电池隔膜-电解液界面结构演化过程原位表征