Lithium-sulfur batteries (LSBs) are regarded as one of the most promising candidates for next-generation energy storage systems. However, the commercialization of LSBs is still hindered by several technical issues, including the notorious polysulfide migration from the cathode to the anode and the sluggish sulfur conversion kinetics. Herein, a quasi-1D hexagonal chalcogenide perovskite, Sr8Ti7S21, is demonstrated as an efficient sulfur host able to overcome these limitations. Experimental results and density functional theory calculations show Sr8Ti7S21 to offer strong lithium polysulfides (LiPS) binding through multiple bond formation. Besides, Sr8Ti7S21 effectively facilitates the kinetics of the LiPS redox reaction. As a result, S@Sr8Ti7S21-based cathodes exhibit excellent initial capacities up to 1315 mAh g−1 at 0.2C, impressive cycling stability with an average capacity decay rate of 0.08% per cycle over 400 cycles at 1C, and a high areal capacity of 6.58 mAh cm−2 under a high sulfur loading of 6.5 mg cm−2. This work reveals the potential capabilities and promising prospects of chalcogenide perovskites in advancing LSBs technology.

The authors thank the support from the projects ENE2016-77798-C4-3-R and NANOGEN (PID2020-116093RB-C43), funded by MCIN/ AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”, by the “European Union”. ICN2 acknowledges funding from Generalitat de Catalunya 2021SGR00457. This study is part of the Advanced Materials programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17.I1) and by Generalitat de Catalunya. ICN2 was supported by the Severo Ochoa program from Spanish MCIN / AEI (Grant No.: CEX2021-001214-S) and was funded by the CERCA Programme / Generalitat de Catalunya. D. Yang thanks the China Scholarship Council for the scholarship support and the funding from the National Natural Science Foundation of China (NSFC) (Grants No. 22305064). Y.H. and H.G. thank the National Natural Science Foundation of China (NSFC) (Grants No. 62104215, No.12004340).

With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001214-S).

Peer reviewed