(364d) Enhanced Lithium/Sulfur Liquid Battery Capacity By Employing Porous Cathode Current Collectors

Negar Mosavati, Steven O. Salleyand K. Y. Simon Ng

Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, MI 48202

Lithium-Sulfur batteries (Li-S) are 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 is a by-product of petroleum and has the advantages of high natural abundance and low cost. Based on the overall reaction: 2Li + S -> Li₂S, it can deliver as much as 1675 mAh/g sulfur (theoretical capacity) with a theoretical specific energy of ~2600 Wh/kg, while displaying an average voltage of ~2.2 V vs. Li/Li⁺. However, the current state of the Li-S battery suffers from several drawbacks, which lead to low active material utilization, poor capacity retention, high self-discharge and short cycle life.

In current research, we have introduced and compared different porous electrically conductive cathode architectures, which restrain the loss of active material, minimize internal impedance, and improve Li-S battery capacity. In order to accomplish a profound understanding of the chemical and electrochemical aspects that influence Li-S battery performance, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge-discharge measurements have been applied. The results would be of great significance to electrode material design for more efficient Li-S batteries.