Engineering single-atom catalysts as multifunctional polysulfide and lithium regulators toward kinetically accelerated and durable lithium-sulfur batteries

作者：Wang, Donghua; Ma, Kaikai; Hao, Jiamao; Zhang, Wenyuan; Shi, Haofeng; Wang, Chengdeng; Xiong, Zhihao; Bai, Zhiming; Chen, Fu-Rong^*; Guo, Junjie; Xu, Bingshe; Yan, Xiaoqin^*; Gu, Yousong^*

来源：Chemical Engineering Journal, 2023, 466: 143182.

DOI：10.1016/j.cej.2023.143182

• Single -atom catalysts
• Polysulfides conversion kinetics
• Multifunctional separator
• Lithium -sulfur batteries

Developing electrocatalyst to ameliorate the shuttling effect of lithium polysulfides (LiPSs), sluggish sulfur redox reaction kinetics and the rampant dendrite growth is of paramount importance for lithium-sulfur (Li-S) batteries. Yet still, the utilization of the most mainstream traditional metal electrocatalytic nanoparticles is far below expectation. Herein, we engineer an exclusive single-atom catalyst with planar Co-N4 coupling of nitrogen-doped graphene mesh (SA-Co/NGM) to achieve exceptional atom utilization efficiency for catalytic conversion of LiPSs. High surface area and ultra-thin two-dimensional texture can not only accommodate high concentration mon-odispersed lithiophilic atomic Co sites, but also guarantee homogenize high-flux Li ion transport, alleviating the formation of Li-dendrites. Critically, the maximized exposure of Co-N4 as a regulator in sulfur electrochemistry can conspicuously suppress the shuttle effect and accelerate bidirectional sulfur redox kinetics via electron delocalization, as demonstrated by a judicious combination of electro-kinetic analysis, in situ spectroscopy and density functional theory (DFT) computations. As expected, the batteries based on a SA-Co/NGM modified separator achieve an ultrahigh rate capability, exceptionally long cycle life and a distinguished favorable areal capacity under high sulfur loading. This work provides a rational design of single-atom catalysts for kinetics -boosted electrocatalysis towards long-lasting Li-S batteries.

• 单位
  北京科技大学