Packing sulfur into carbon framework for high volumetric performance lithium-sulfur batteries

Abstract

Low volumetric performance is a common bottleneck of carbon-based electrode materials for practical applications, owing to the low density of porous carbons caused by the intrinsic void space. Specifically, lithium-sulfur (Li-S) batteries as a hot topic of next-generation energy storage devices face the same dilemma that we have to balance their intrinsically electrochemical performance and volumetric performance. The use of conductive porous carbon materials in the cathode of Li-S batteries, such as mesoporous carbon, carbon nanotube and graphene-derived carbons, can effectively accelerate the reaction kinetics, improve the electrochemical performance of sulfur cathode and promote the practical application of insulting sulfur. However, addition of these materials results in massive void space in the electrode, which cannot meet the requirement of compact structure in real applications. Such electrodes usually deliver relatively low volumetric performance even though their gravimetric performance can reach a high value.