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Understanding the interactions between lithium polysulfides and N-doped graphene using density functional theory calculations

Journal Article


Abstract


  • To understand the origin of the cycling performance improvement observed in lithium-sulfur (Li-S) batteries based on N-doped carbon materials, the interactions between lithium polysulfides (LiPSs) and N-doped graphene (N-G) with different doping configurations have been investigated by density functional theory calculations. It has been found that only N-G with clustered pyridinic N-dopants can strongly attract LiPSs with large enough binding energies to effectively anchor the soluble LiPSs, due to (i) an enhanced attraction between Li ions in LiPSs and pyridinic N-dopants and/or (ii) an additional attraction between S anions in LiPSs and Li ions captured by pyridinic N-dopants. This study has, for the first time, provided a fundamental understanding on the origin of the effective anchoring of LiPSs by N-doped carbon materials, which suppresses the shuttling of LiPSs and produces significant improvement in the cycling performance of Li-S batteries. These findings can also guide the design of more effective N-doped carbons or other N-rich materials for Li-S batteries, preventing the undesirable LiPS shuttling.

UOW Authors


  •   Liang, Ji (external author)

Publication Date


  • 2016

Citation


  • Yin, L. C., Liang, J., Zhou, G. M., Li, F., Saito, R., & Cheng, H. M. (2016). Understanding the interactions between lithium polysulfides and N-doped graphene using density functional theory calculations. Nano Energy, 25, 203-210. doi:10.1016/j.nanoen.2016.04.053

Scopus Eid


  • 2-s2.0-84965045886

Start Page


  • 203

End Page


  • 210

Volume


  • 25

Issue


Place Of Publication


Abstract


  • To understand the origin of the cycling performance improvement observed in lithium-sulfur (Li-S) batteries based on N-doped carbon materials, the interactions between lithium polysulfides (LiPSs) and N-doped graphene (N-G) with different doping configurations have been investigated by density functional theory calculations. It has been found that only N-G with clustered pyridinic N-dopants can strongly attract LiPSs with large enough binding energies to effectively anchor the soluble LiPSs, due to (i) an enhanced attraction between Li ions in LiPSs and pyridinic N-dopants and/or (ii) an additional attraction between S anions in LiPSs and Li ions captured by pyridinic N-dopants. This study has, for the first time, provided a fundamental understanding on the origin of the effective anchoring of LiPSs by N-doped carbon materials, which suppresses the shuttling of LiPSs and produces significant improvement in the cycling performance of Li-S batteries. These findings can also guide the design of more effective N-doped carbons or other N-rich materials for Li-S batteries, preventing the undesirable LiPS shuttling.

UOW Authors


  •   Liang, Ji (external author)

Publication Date


  • 2016

Citation


  • Yin, L. C., Liang, J., Zhou, G. M., Li, F., Saito, R., & Cheng, H. M. (2016). Understanding the interactions between lithium polysulfides and N-doped graphene using density functional theory calculations. Nano Energy, 25, 203-210. doi:10.1016/j.nanoen.2016.04.053

Scopus Eid


  • 2-s2.0-84965045886

Start Page


  • 203

End Page


  • 210

Volume


  • 25

Issue


Place Of Publication