Unlocking dual-site regulation in perovskite-modified separators for efficient polysulfide conversion in lithium-sulfur batteries

초록

Lithium-sulfur (Li-S) batteries are regarded as highly promising high energy density systems; however, their commercialization is severely hindered by the "shuttle effect" originating from the dissolution of polysulfides. Developing high-performance catalysts to accelerate redox kinetics is crucial for addressing these fundamental challenges. In this work, LaCoO3 (LCO) perovskite nanofibers were fabricated via electrospinning, followed by precise A-site (Sr) and B-site (Fe) doping to construct a dual-site regulated La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) catalyst. Our research suggests that LSCF provides a favorable balance between polysulfide adsorption and electrocatalytic activity. Electrochemical measurements show that LSCF significantly accelerates reaction kinetics and active material utilization. Consequently, the battery exhibits exceptional long-term stability over 500 cycles at 2C, with an ultra-low capacity decay rate of 0.04% per cycle. Furthermore, the stable operation of pouch cells underscores the practical viability of the LSCF perovskite catalyst. This study provides valuable insights into the rational design of high-performance perovskite catalysts for advanced Li-S batteries.

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