Modularized sulfur storage achieved by 100% space utilization host for high performance lithium-sulfur batteries

Abstract

Popularization of lithium-sulfur batteries (LSBs) is still hindered by shuttle effect and volume expansion. Herein, a new modularized sulfur storage strategy is proposed to solve above problems and accomplished via employing 100% space utilization host material of cobalt loaded carbon nanoparticles derived from ZIF-67. The modular dispersed storage of sulfur not only greatly increases the proportion of active sulfur, but also inhibits the occurrence of volume expansion. Meanwhile, 100% space utilization host material can greatly improve the conductivity of the cathode, provide a larger electrolyte wetting interface and effectively suppress the shuttle effect. Moreover, loaded cobalt particles have high catalytic activity for electrochemical reaction and can effectively improve the redox kinetics. The cell with new cathode host material carbonized at 650 °C (ZIF-67 (650 °C)) exhibits superior rate performance and can maintain a high specific capacity of 950 mAh/g after 100 cycles at 0.2 C, showing a good cycle stability.