Atomic‐Level Modulation of Imine and Cobalt Enables a Homogeneous Co <sub>5.47</sub> N Catalyst for High‐Performance Lithium‐Sulfur Batteries
Liqiang Mai, Hui Liu, Zhi Cheng, Jiawei He, Huifang Li, Lisheng Zhang, Tao Liu, Xiaojun Wang, Peng Wang, Zhiming Liu, Guanglei Cui
Abstract
Abstract Electrocatalyst presents a promising strategy for enhancing sulfur utilization and cycling stability in lithium‐sulfur (Li‐S) batteries, especially under demanding operational conditions. However, conventional catalytic strategies demonstrate undesirable effects in high‐loading lithium‐sulfur batteries, primarily attributed to the absence of efficient catalyst dispersion strategy. In this work, it successfully anchored a diverse range of Co‐containing catalysts uniformly onto the COF‐derived carbon through the unique chelation between cobalt atoms and imine groups. This strategy greatly enhances catalytic efficiency and also prevents the formation of “dead” catalysts, maximizing catalyst utilization. Experimental measurements and simulations reveal that the Co 5.47 N nanocrystal integrated with COF‐derived carbon (Co 5.47 N@NC) demonstrates remarkable catalytic efficiency in accelerating polysulfide conversion, primarily owing to the significant modulation of the d‐band center of cobalt atoms within the Co 5.47 N@NC. Remarkably, the Li‐S battery with Co 5.47 N@NC achieves a specific capacity of 1288 mAh g −1 at 0.3 C and maintains 92% capacity retention over 200 cycles. The Co 5.47 N@NC system with a sulfur loading of 5.7 mg cm −2 and an E/S ratio of 4.0 µL mg −1 , still sustains a specific capacity of 1314 mAh g −1 . Consequently, a 1.0 Ah‐level pouch cell delivers an energy density of 411 Wh kg −1 and maintains stable cycling.