High Sulfur Loading in Hierarchical Porous Carbon Rods Constructed by Vertically Oriented Porous Graphene-Like Nanosheets for Li-S Batteries

The utilization of porous carbon frameworks as hosts for sulfur loading is an important theme in current Li-S battery research. Unfortunately, the high loading of insulating sulfur often leads to low specific capacities, poor rate properties, and rapid capacity loss. To address this challenge, a facile templating route to fabricate a novel host material, hierarchical porous carbon rods constructed by vertically oriented porous graphene-like nanosheets (HPCR) is presented. With a high specific surface area, ultralarge pore volume, hierarchical porous structures, and ideal ion transfer pathways, HPCR is a promising candidate for high sulfur loading. When used as the active material for a sulfur cathode, the HPCR-S composite with 78.9 wt% sulfur exhibits excellent rate performance (646 mAh g(sulfur)(-1) at 5 C) and cycling stability (700 mAh g(sulfur)(-1) after 300 cycles at 1 C). Even with a sulfur content of 88.8 wt%, the HPCR-S composite, without any additional protective polymer coating, still delivers a good rate performance (545 mAh g(sulfur)(-1) at 3 C) and cycling stability (632 mAh g(sulfur)(-1) after 200 cycles at 1 C). More importantly, the high sulfur loading (88.8 wt%) ensures that the HPCR-S composite has a high energy density (880 mAh cm(cathode)(-3) after 200 cycles at 1 C).