(287f) A High Capacity Carbon Free Cathode Material for Lithium/Dissolved Polysulfide Batteries

Lithium-Sulfur batteries (Li-S) are considered as one of the most attractive power sources and promising candidates to replace the conventional state-of-the-art lithium ion batteries. Sulfur as a cathode active material  offers a high theoretical capacity of 1675  mAh g^-1 sulfur with a theoretical specific energy of ~2600 Wh/kg, and has the advantages of high natural abundance and low cost. However, it suffers from several drawbacks, which lead to low active material utilization, poor capacity retention, high self-discharge and short cycle life. Much of the research on cycling and capacity performance of cathodes has focused on enhancing carbon materials electrical conductivity and ability of absorbing and accommodating polysulfides in order to enhance Li/S battery performance.

In current research, we have introduced and compared different carbon free electrically conductive cathode materials, which restrains the loss of active material, minimize internal impedance, and improve Li-S battery cell capacity retention. In order to accomplish a profound understanding of the chemical and electrochemical aspects that influence Li-S performance, X-ray diffraction (XRD), scanning electron microscopy (SEM), in addition to electrochemical spectra (EIS) and cyclic voltammetry (CV) measurement, have been applied. The results would be of great significance to improve the efficiency of Li/S batteries.