Embedding sulfur into N-doped carbon nanospheres as enhanced cathode for high-performance lithium-sulfur batteries

Abstract

Lithium-sulfur (Li-S) batteries are considered as one of the most efficient power candidates owing to high energy density about 7–10 times larger than the commercial cathode materials. However, its practical application is impeded by severe “shuttle effect” and low cycle stability. As a consequence, in this work, we report N-doped carbon nanospheres (N-CNSs) composited with S as cathode for Li-S batteries. The stacked carbon nanosphere structure can not only improve the conductivity of cathode, but also work as barriers to retard diffusion of intermediate polysulfide. Owing to the unique structure, the N-CNSs/S cathode exhibits superior electrochemical performances with high specific capacity (1228mAhg−1 at 0.1C), and excellent rate capability as well as good cyclic life. Our smart designed strategy may promote the development of high performance Li-S batteries.