Electrochemical Performance of All-Solid-State Li/S Batteries with Sulfur-Based Composite Electrodes Prepared by Mechanical Milling at High Temperature

Sulfur-nanocarbon composites were prepared by mechanical milling at high temperature (155 degrees C), and the electrochemical performance of all-solid-state Li/S batteries was investigated with Li2S-P2S5 solid electrolytes. We aimed to increase the sulfur content in the sulfur-based composite electrodes to enhance the energy density in the Li/S batteries. The composites included 50 wt% sulfur, which is twice as high as that in the all-solid-state Li/S batteries that use sulfide-based solid electrolytes reported to date, and high-temperature mechanical milling resulted in a small sulfur particle size with a large contact area between the particles. The improved composites are mainly responsible for the excellent cyclability (1050 mAhg(-1) for 50 cycles), high gravimetric energy density (1007 Whkg(-1)), and good rate capability of the assembled batteries. These composites are promising positive-electrode materials for rechargeable Li/S batteries with high energy density. This approach of mechanical milling at high temperature is widely applicable and can be extended to a variety of materials in versatile energy devices as well as rechargeable lithium batteries.