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

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, we report an in-situ cathode-interweaving strategy based on metalloporphyrin based covalent-bonding organic polymer (M-COP, M = Mn, Ni and Zn) binders 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 PVDF) 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 ), and the utilization-rate of sulfur is as high as 81.8%, which is the optimal binder performance in Li-S battery as far as we know and has much potential to meet the "4H" and "4L" criteria. In addition, theoretical calculations reveal the vital roles of metalloporphyrin and thiourea-groups in enhancing the battery-performance. This article is protected by copyright. All rights reserved.