Concrete-like high sulfur content cathodes with enhanced electrochemical performance for lithium-sulfur batteries

Nowadays, lithium-sulfur batteries have attracted numerous attention due to their high specific capacity, high energy density, low cost and environmental benignancy. However, there are some critical challenges to be overcome such as low electronic conductivity and capacity fading caused by shuttle effect. Many attempts have been conducted to improve the electrochemical performance by designing effective sulfur hosts. In this paper, we synthesize a concrete-like sulfur/carbon cathode with high sulfur content (84%) by using 3D macroporous hosts with high pore volume. Sophisticated strategies of using polarized carbon framework and polymer coating are applied to synergistically control the dissolution of polysulfides so that the capacity retention and high rate performance can be remarkably enhanced. As a result, the composite exhibits a specific discharge capacity of 820 mAh g(-1) at a discharge current of 800 mA g(-1) (approximate to 0.5 C) after 100 cycles, calculated on the integrated mass of composite, which is superior to most report results. (C) 2019 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.