Toward Complete Transformation of Sodium Polysulfides by Regulating the Second-Shell Coordinating Environment of Atomically Dispersed Fe

Bai, Ruilin; Lin, Qiaosong; Li, Xinyu; Ling, Fangxin; Wang, Huijuan; Tan, Sha; Hu, Lingxiang; Ma, Mingze; Shao, Yu; Wu, Xiaojun; Rui, Xianhong; Hu, Enyuan; Yao, Yu; Yu, Yan

doi:10.1002/ange.202218165

DOE OSTI · 1963586

Toward Complete Transformation of Sodium Polysulfides by Regulating the Second-Shell Coordinating Environment of Atomically Dispersed Fe

Bai, Ruilin·Lin, Qiaosong·Li, Xinyu·Ling, Fangxin·Wang, Huijuan·Tan, Sha·Hu, Lingxiang·Ma, Mingze·Shao, Yu·Wu, Xiaojun·Rui, Xianhong·Hu, Enyuan·Yao, Yu·Yu, Yan

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Abstract

Room temperature sodium-sulfur (RT Na-S) batteries are highly competitive as potential energy storage devices. Nevertheless, their actually achieved reversible capacities are far below the theoretical value due to incomplete transformation of polysulfides. Herein, atomically dispersed Fe-N/S active center by regulating the second-shell coordinating environment of Fe single atom is proposed. The Fe-N4S2 coordination structure with enhanced local electronic concentration around the Fermi level is revealed via synchrotron radiation X-ray absorption spectroscopy (XAS) and theoretical calculations, which can not only significantly promote the transformation kinetics of polysulfides, but induce uniform Na deposition for dendrite-free Na anode. Here as a result, the obtained S cathode delivers a high initial reversible capacity of 1590 mAh g-1, nearly the theoretical value. Here this work opens up a new avenue to facilitate the complete transformation of polysulfides for RT Na-S batteries.

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25 ENERGY STORAGE Fe single atom RT Na-S batteries catalysis coordinating environment transformation kinetics

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Bai, Ruilin, Lin, Qiaosong, Li, Xinyu, Ling, Fangxin, Wang, Huijuan, Tan, Sha, Hu, Lingxiang, Ma, Mingze, Shao, Yu, Wu, Xiaojun, Rui, Xianhong, Hu, Enyuan, Yao, Yu, Yu, Yan. 2023-03-14. Toward Complete Transformation of Sodium Polysulfides by Regulating the Second-Shell Coordinating Environment of Atomically Dispersed Fe. https://doi.org/10.1002/ange.202218165

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