N, S‐Coordinated Co Single Atomic Catalyst Boosting Adsorption and Conversion of Lithium Polysulfides for Lithium‐Sulfur Batteries

作者：Kun Liu, Xinyang Wang, Shuai Gu, Huimin Yuan, Feng Yi Jiang, Yingzhi Li, Wen Yuan Tan, Qiurong Long, Jingjing Chen, Zhenghe Xu, Zhouguang Lu · 发表于：Small · 年份：2022 · DOI：10.1002/smll.202204707 · 被引用次数：77 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Polyoxometalates: Synthesis and Applications

Abstract Boosting reversible solid‐liquid phase transformation from lithium polysulfides to Li2S and suppressing the shuttling of lithium polysulfides from the cathode to the lithium anode are critical challenges in lithium‐sulfur batteries. Here, sulfiphilic single atomic cobalt implanted in lithiophilic heteroatoms‐dopped carbon (SACo@HC) matrix with a CoN3S structure for high‐performance lithium‐sulfur batteries is reported. Density functional theory calculation and in situ experiments demonstrate that the optimal CoN3S structure in SACo@HC can effectively improve the adsorption and redox conversion efficiency of lithium polysulfides. Consequently, the S‐SACo@HC composite with sulfur loading of 80 wt% delivers a high capacity of 1425.1 mAh g−1 at 0.05 C and outstanding rate performance with 745.9 mAh g−1 at 4 C. Furthermore, a capacity of 680.8 mAh g−1 at 0.5 C with a low electrolyte/sulfur ratio (6 µL mg−1) can be achieved even after 300 cycles. With the harsh conditions of lean electrolyte (E/S = 4 µL mg−1) and high sulfur loading (5.4 mg cm−2), a superior area capacity of 5.8 mAh cm−2 can be obtained. This work contributes to building a profound understanding of the adsorption and interface engineering of lithium polysulfides and provides ideas to tackle the long‐standing polysulfide shuttle problem of lithium‐sulfur batteries.