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

Abstract 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.