In Situ Interweaved High Sulfur Loading Li–S Cathode by Catalytically Active Metalloporphyrin Based Organic Polymer Binders

• Published in: Advanced materials (Weinheim) Vol. 35; no. 7; pp. e2208846 - n/a
• Main Authors: Yao, Xiaoman, Guo, Can, Song, Chunlei, Lu, Meng, Zhang, Yuluan, Zhou, Jie, Ding, Hui‐Min, Chen, Yifa, Li, Shun‐Li, Lan, Ya‐Qian
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01-02-2023
• Subjects: Adsorption; Catalysis; Cathodes; in situ interweaving strategy; lithium polysulfides; Li–S cathode; Materials science; metalloporphyrin; polymer binder; Polymers; Polysulfides; Polyvinylidene fluorides; Sulfur; Vinylidene fluoride; lithium polysulfides; Li-S cathode; in situ interweaving strategy; polymer binder; metalloporphyrin
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202208846

The elaborate design of powerful Li–S binders with extended‐functions like polysulfides adsorption/catalysis and Li+ hopping/transferring in addition to robust adhesion‐property has remained a challenge. Here, an in situ cathode‐interweaving strategy based on metalloporphyrin based covalent‐bonding organic polymer (M‐COP, M = Mn, Ni, and Zn) binders is reported for the first time. Thus‐produced functional binders possess excellent mechanical‐strengths, polysulfides adsorption/catalysis, and Li+ hopping/transferring ability. Specifically, the modulus of Mn‐COP can reach up to ≈54.60 GPa (≈40 times higher than poly(vinylidene fluoride)) and the relative cell delivers a high initial‐capacity (1027 mAh g‐1, 1 C and 913 mAh g‐1, 2 C), and excellent cycling‐stability for >1000 cycles even at 4 C. The utilization‐rate of sulfur can reach up to 81.8% and the electrodes based on these powerful binders can be easily scale‐up fabricated (≈20 cm in a batch‐experiment). Noteworthy, Mn‐COP based cell delivers excellent capacities at a high sulfur‐loading (8.6 mg cm‐2) and low E/S ratio (5.8 µL mg‐1). In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea‐groups in enhancing the battery‐performance.
An in situ cathode‐interweaving strategy based on metalloporphyrin organic polymer (M‐COP, M = Mn, Ni, and Zn) binders is proposed and excellent performance is achieved in Li–S battery.