Guoran Li

Abstract:

Lithium sulfur battery is one of the most promising rechargeable batteries with high theoretical energy density. Usually, sulfur-carbon composites are used as cathode materials to improve electrical conductivity and restrain dissolution of lithium polysulfide. It is noteworthy that loading amount of sulfur in a sulfur-carbon composite cathode material is very vital to obtain finally high energy density of a lithium-sulfur battery. Therefore, it is an important question how to achieve a high coefficient of utilization of sulfur in a cathode material with high sulfur loading. In our works, several kinds of sulfur-carbon composites with different sulfur loading are discussed on utilization coefficient of sulfur. A sulfur-carbon composite with a sulfur content of 81.7 wt% prepared with a hybrid carbon substrate as sulfur immobilizer delivers a high initial capacity of 837.3 and 685.9 mA h g-1 (composite) at the current densities of 80 and 160 mA g-1, respectively. After 150 cycles at the current density of 160 mA g-1, the discharge capacity remains at 554.4 mA h g-1, indicating a low capacity fading.