Novel Approaches for Engineering Li2S Cathodes of Lithium Sulfur Batteries

Lithium–sulfur (Li–S) batteries are attractive as the next generation of energy storage devices for the applications in portable electronics and electric vehicles due to their high energy density. In the recent years, various novel electrodes and electrolytes have been tried to enhance the battery performance. However, these designs have not completely addressed the issue of low capacity retention. Herein, we proposed a novel template approach to engineer C@Li₂S@C with double-core shell structure. Via this method, the outside carbon shell offers a pathway to electrons and enables a high electronic conductivity. The Li₂S layer with sphere structures is expected to be well encapsulated by the carbon shell. In the early stage testing, the cells yield an initial capacity of around 910 mA h/g. More importantly, there are only small decays after the 2^nd cycle and little degradations from the 16^th cycle to the 53^rd cycle with a high retained capacity of ~570 mA h/g, which means the capacity retention is excellent with an ultrahigh Comloubic efficiency of 96%.