Modified nano-CaCO3 hard template method for hierarchical porous carbon powder with enhanced electrochemical performance in lithium-sulfur battery

Abstract

Lithium-sulfur (Li-S) battery was the most promising energy storage devices with ultrahigh energy density (2600 Wh kg−1). But it was impeded by poor electronic conductivity, serious shuttle effect, and enormous volume expansion. Herein, hierarchical porous carbons were simply prepared by a modified nano-CaCO3 hard-template method from glucose. The template-removal step was modified from HCl washing to HCl soaking. This allowed the microstructure of carbon product significantly involved. Furthermore, the mass ratio of CaCO3 nanoparticles and glucose played an important role in booming of hierarchical porous and specific surface area. When integrated with S, functioned as cathode in Li-S battery, improved electrochemical performances were exhibited, such as high initial discharge capacity and good capacity retention. This modified hard-template method suggested a promising way to fabricate hierarchical porous carbon matrix available to apply in advanced Li-S battery.