Sieving effect integration with asymmetrically coordinated catalytic chemistry Realize optimized polysulfide regulation in Lithium-Sulfur batteries
Shupeng Zhao, Chuyin Ma, Chengjiao Zhao, Hao Meng, Xiaomin Zhang, Jiayi Wang, Jiawen Chen, Mingliang Jin, Lin Yang, Xin Wang, Zhongwei Chen
Abstract
Lithium-sulfur (Li-S) batteries are regarded as a promising next-generation rechargeable battery system due to their high energy density and low cost. However, their practical application has been hindered by severe polysulfide shuttling and sluggish sulfur conversion kinetics. Effective integration of polysulfide regulation, including adsorption and catalytic conversion, is critical for advancing Li-S battery commercialization. Here, the sieving effect is integrated with asymmetrically coordinated catalytic chemistry, utilizing asymmetric cobalt single-atom catalysts (Co-C 2 N 2 ) anchored on custom-designed porous carbon molecular sieves (CMS) within the Li-S battery. The tailored CMS, with uniformly distributed micropores (∼5.7 Å), smaller than the polysulfide molecules, simultaneously block polysulfide diffusion while allowing efficient lithium-ion transport. Beyond physical sieving, catalytic activity is further enhanced through cobalt single-atom asymmetric coordination, promoting high sulfur affinity and accelerating conversion kinetics. As a result, the Co-CMS separator achieves a high reversible specific capacity of 1018.7 mAh g −1 at 1C and demonstrates a low capacity fade of 0.047 % per cycle over 500 cycles. Even with a high sulfur loading of 6.1 mg cm −2 , the areal capacity reaches 6.85m Ah cm −2 . This study illustrates that the synergy between sieving effects and coordination chemistry provides an effective strategy for extending the operational life of Li-S batteries.