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Architecting Freestanding Sulfur Cathodes for Superior Room-Temperature Na¿S Batteries

Journal Article


Abstract


  • Room-temperature sodium–sulfur (RT Na–S) batteries have attracted extensive attention because of their low cost and high specific energy. RT Na–S batteries, however, usually suffer from sluggish reaction kinetics, low reversible capacity, and short lifespans. Herein, it is shown that chain-mail catalysts, consisting of porous nitrogen doped carbon nanofibers (PCNFs) encapsulating Co nanoparticles (Co@PCNFs), can activate sulfur via electron engineering. The chain-mail catalysts Co@PCNFs with a micrograde hierarchical structure as a freestanding sulfur cathode (Co@PCNFs/S) can provide space for high mass loading of sulfur and polysulfides. The electrons can rapidly transfer from chain-mail catalysts to sulfur and polysulfides during discharge–charge processes, therefore boosting its conversion kinetics. As a result, this freestanding Co@PCNFs/S cathode achieves a high sulfur loading of 2.1 ± 0.2 mg cm−2, delivering a high reversible capacity of 398 mA h g−1 at 0.5 C (1 C = 1675 mA g−1) over 600 cycles and superior rate capability of an average capacity of 240 mA h g−1 at 5 C. Experimental results, combined with density functional theory calculations, demonstrate that the Co@PCNFs/S can efficiently improve the conversion kinetics between the polysulfides and Na2S via transferring electrons from Co to them, thereby realizing efficient sulfur redox reactions.

Publication Date


  • 2021

Citation


  • Yang, H., Zhou, S., Zhang, B. W., Chu, S. Q., Guo, H., Gu, Q. F., . . . Dou, S. X. (2021). Architecting Freestanding Sulfur Cathodes for Superior Room-Temperature Na¿S Batteries. Advanced Functional Materials, 31(32). doi:10.1002/adfm.202102280

Scopus Eid


  • 2-s2.0-85107028757

Volume


  • 31

Issue


  • 32

Abstract


  • Room-temperature sodium–sulfur (RT Na–S) batteries have attracted extensive attention because of their low cost and high specific energy. RT Na–S batteries, however, usually suffer from sluggish reaction kinetics, low reversible capacity, and short lifespans. Herein, it is shown that chain-mail catalysts, consisting of porous nitrogen doped carbon nanofibers (PCNFs) encapsulating Co nanoparticles (Co@PCNFs), can activate sulfur via electron engineering. The chain-mail catalysts Co@PCNFs with a micrograde hierarchical structure as a freestanding sulfur cathode (Co@PCNFs/S) can provide space for high mass loading of sulfur and polysulfides. The electrons can rapidly transfer from chain-mail catalysts to sulfur and polysulfides during discharge–charge processes, therefore boosting its conversion kinetics. As a result, this freestanding Co@PCNFs/S cathode achieves a high sulfur loading of 2.1 ± 0.2 mg cm−2, delivering a high reversible capacity of 398 mA h g−1 at 0.5 C (1 C = 1675 mA g−1) over 600 cycles and superior rate capability of an average capacity of 240 mA h g−1 at 5 C. Experimental results, combined with density functional theory calculations, demonstrate that the Co@PCNFs/S can efficiently improve the conversion kinetics between the polysulfides and Na2S via transferring electrons from Co to them, thereby realizing efficient sulfur redox reactions.

Publication Date


  • 2021

Citation


  • Yang, H., Zhou, S., Zhang, B. W., Chu, S. Q., Guo, H., Gu, Q. F., . . . Dou, S. X. (2021). Architecting Freestanding Sulfur Cathodes for Superior Room-Temperature Na¿S Batteries. Advanced Functional Materials, 31(32). doi:10.1002/adfm.202102280

Scopus Eid


  • 2-s2.0-85107028757

Volume


  • 31

Issue


  • 32