An adsorption-catalytic conversion catalyst Fe2O3@C-modified separator for boosting conversion of lithium polysulfides and long-life lithium-sulfur batteries

• Published in: Ionics Vol. 30; no. 10; pp. 6025 - 6035
• Main Authors: Deng, Teng, Men, Xinliang, Chen, Liping, Zu, Guannan, Wang, Juan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2024; Springer Nature B.V
• Subjects: Adsorption; Catalysts; Catalytic converters; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Decay rate; Discharge; Electrochemical analysis; Electrochemistry; Energy Storage; Kinetics; Lithium; Lithium sulfur batteries; Metal oxides; Optical and Electronic Materials; Polysulfides; Reaction kinetics; Renewable and Green Energy; Separators; Sulfur; Li–S batteries; Lithium polysulfides; Redox reaction kinetics; Modified separator
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-024-05706-y

Lithium-sulfur (Li–S) batteries are a highly promising energy storage system due to their ultra-high theoretical energy density. However, Li–S batteries, based on the dissolved deposition mechanism, suffer from lithium polysulfides (LiPSs) shuttling and slow conversion kinetics, causing severe capacity decay during operation. Herein, we have improved the battery life by a LiPSs adsorption-rapid catalytic conversion Fe 2 O 3 @C catalyst in the modified separator. The Fe 2 O 3 @C modified separator first physically restricts LiPSs and then rapidly converts the captured LiPSs through the polar adsorption and catalytic ability of Fe 2 O 3 , greatly promoting the LiPS conversion kinetics in Li–S batteries. The battery with Fe 2 O 3 @C exhibits excellent electrochemical performance. In detail, the initial discharge specific capacity of the first discharge is 1043.26 mAh g −1 at 0.05 C; the specific capacity is maintained at 676.80 mAh g −1 after 100 cycles at 0.2 C. The high specific capacity of 389.3 mAh g −1 is maintained even after 1000 cycles with a capacity decay of 0.055% per cycle. This work provides a way to improve sulfur conversion kinetics through metal oxides.