Synergistic design of core-shell VS@C hosts and homogeneous catalysts promoting polysulfide chemisorption and conversion for Li-S batteries

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Vol. 11; no. 5; pp. 2233 - 2245
• Main Authors: Tan, Ke, Tan, Zhaolin, Liu, Sen, Zhao, Guoqiang, Liu, Yang, Hou, Linrui, Yuan, Changzhou
• Format: Journal Article
• Published: 31.01.2023
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d2ta09373a

Li-S batteries (LSBs), owing to their superior energy density, cost-efficiency, and environment-friendliness, are established as one of the most potential next-generation electrochemical energy storage systems. However, the shuttle effect of lithium polysulfides (LPSs) and the poor conductivity of active substances are the main challenges to their practical applications. Herein, we propose a synergistic strategy involving heterogeneous and homogeneous catalysts. First, MIL-47 as-derived core-shell carbon nanorods decorated with a V 3 S 4 nanosheet shell (V 3 S 4 @C) were smartly constructed and applied as the host material for sulfur cathodes. The resulting V 3 S 4 @C not only enhanced the electronic conductivity of the integrated cathode but promoted LPSs chemisorption and conversion as heterogeneous catalysts. The optimized Co(C 5 H 5 ) 2 was further introduced into the electrolyte as a homogeneous catalyst, improving the conversion efficiency of LPSs and electrolyte wettability. Benefiting from the synergistic contributions of the V 3 S 4 @C host and the homogeneous catalyst Co(C 5 H 5 ) 2 , the assembled LSBs with S/V 3 S 4 @C as the cathode exhibited outstanding long-life cycling performance and high-rate behavior, particularly in cases with high sulfur loading and low electrolyte dosage. More significantly, our work promises a feasible pathway for commercial applications of advanced LSBs. The synergistic design of 1D core-shell V 3 S 4 @C hosts and homogeneous catalyst Co(C 5 H 5 ) 2 is proposed to promote the chemisorption and conversion kinetics of polysulfides towards advanced Li-S batteries with high areal S loading and low E/S ratio.