TY - JOUR
T1 - Synergetic effect of spatially separated dual co-catalyst for accelerating multiple conversion reaction in advanced lithium sulfur batteries
AU - Zhao, Zhenxin
AU - Yi, Zonglin
AU - Li, Huijun
AU - Pathak, Rajesh
AU - Yang, Zhewei
AU - Wang, Xiaomin
AU - Qiao, Qiquan
N1 - Publisher Copyright:
© 2020 Elsevier Ltd
PY - 2021/3
Y1 - 2021/3
N2 - The enhanced chemical immobilization and catalytic conversion of polysulfides (LiPS) intermediates are considered a promising solution to improve the electrochemical performance in lithium-sulfur batteries. However, the role of catalysts on catalytic mechanism of distinctive selectivity is still not understood and overlooked. Herein, a dual-functional strategy, composed of Fe3O4 nanoparticles/hierarchical porous carbon (Fe3O4/HPC) cathode and FeP/HPC modified separator, is proposed to improve anchoring and catalyzing of LiPS, ensure uniform Li2S deposition and reduce the dead sulfur. The systematic theoretical calculation reveals that the Fe3O4 has the stronger binding energy with LiPS (Li2S4 and Li2S6) due to the Fe-S bonds and Li-O bonds. The variations in the catalytic performance of Fe3O4 and FeP are due to the shifts of p band center. Especially, Fe3O4 and FeP tend to selectively catalyze the solid-liquid reaction and liquid-liquid-solid conversion, respectively. Thus, the synergistic effects of dual-catalysts in spatial separation help to achieve excellent cycling stability with an ultralow capacity decay rate of 0.083% over 1000 cycles at 1 C. Even with a high areal sulfur loading of 5.73 mg cm−2 and a cruel current density of 0.01 C, the cells can still keep a low shuttle factor of 0.08, demonstrating the effective inhibition of shuttle effect. This work offers novel insights for designing a dual-functional structure in lithium-sulfur batteries.
AB - The enhanced chemical immobilization and catalytic conversion of polysulfides (LiPS) intermediates are considered a promising solution to improve the electrochemical performance in lithium-sulfur batteries. However, the role of catalysts on catalytic mechanism of distinctive selectivity is still not understood and overlooked. Herein, a dual-functional strategy, composed of Fe3O4 nanoparticles/hierarchical porous carbon (Fe3O4/HPC) cathode and FeP/HPC modified separator, is proposed to improve anchoring and catalyzing of LiPS, ensure uniform Li2S deposition and reduce the dead sulfur. The systematic theoretical calculation reveals that the Fe3O4 has the stronger binding energy with LiPS (Li2S4 and Li2S6) due to the Fe-S bonds and Li-O bonds. The variations in the catalytic performance of Fe3O4 and FeP are due to the shifts of p band center. Especially, Fe3O4 and FeP tend to selectively catalyze the solid-liquid reaction and liquid-liquid-solid conversion, respectively. Thus, the synergistic effects of dual-catalysts in spatial separation help to achieve excellent cycling stability with an ultralow capacity decay rate of 0.083% over 1000 cycles at 1 C. Even with a high areal sulfur loading of 5.73 mg cm−2 and a cruel current density of 0.01 C, the cells can still keep a low shuttle factor of 0.08, demonstrating the effective inhibition of shuttle effect. This work offers novel insights for designing a dual-functional structure in lithium-sulfur batteries.
KW - Lithium-sulfur batteries
KW - Mechanistic understanding
KW - Multistep polysulfides conversion
KW - Polysulfides adsorption
KW - Stepwise electrocatalysis
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U2 - 10.1016/j.nanoen.2020.105621
DO - 10.1016/j.nanoen.2020.105621
M3 - Article
AN - SCOPUS:85097350372
SN - 2211-2855
VL - 81
JO - Nano Energy
JF - Nano Energy
M1 - 105621
ER -