Characterization of Sulfur/Graphitized Mesocarbon Microbeads Composite Cathodes for Li-S Batteries

Abstract

Cathode optimization is vital for improving the performance of Li-S batteries. Various carbon materials with special morphologies have been proposed and verified to form optimized sulfur/carbon (S/C) cathodes owning high cycling and rate performances. However, the high cost and complexity of material preparation processes hinder their commercialization. Herein, graphitized mesocarbon microbeads (g-MCMB) were used to form sulfur/carbon cathodes for Li-S battery. By simply dry-mixing sulfur powder with g-MCMB, S/g-MCMB cathodes were formed and characterized by galvanostatic charge-discharge tests, electrochemical impedance spectroscopy and scanning electron microscopy. Compared with S/C cathodes using acetylene black, S/g-MCMB cathodes show better cycling performance, but worse rate performance, which can be attributed to the size and morphologies of g-MCMB particles.