SYNTHESIS AND ELECTROCHEMICAL PERFORMANCE OF SULFUR/ HIERARCHICALLY POROUS CARBON COMPOSITES

摘要

The lithium sulfur batteries have increasing attention due to their higher theoretical specific capacity of 1672 mAh g‐1 against lithium, which is almost ten times greater than that of commercially used transition-metal phosphates and oxides. The element sulfur, as the active mass of the cathode of the lithium sulfur battery, has many valuable characteristics, such as low equivalent weight, extremely low cost, and nontoxicity. However, it has been difficult to develop a practical Li-S battery because of the highly insulating nature of sulfur (5× 10‐30 S cm‐1 at 25 °C) and the high solubility of lithium polysulfides as intermediate products generated during the charge and discharge process. These problems cause poor cycle ability and low utilization efficiency of the active mass.