A Comprehensive Approach toward Stable Lithium-Sulfur Batteries with High Volumetric Energy Density

A comprehensive approach is reported to construct stable and high volumetric energy density lithium-sulfur batteries, by coupling a multifunctional and hierarchically structured sulfur composite with an in-situ cross-linked binder. Through a combination of first-principles calculations and experimental studies, it is demonstrated that a hybrid sulfur host composed by alternately stacking graphene and layered graphitic carbon nitride embraces high electronic conductivity as well as high polysulfide adsorptivity. It is further shown that the cross-linked elastomeric binder empowers the hierarchical sulfur composites-multi-microns in size-with the ability to form crack-free and compact high-loading electrodes using traditional slurry processing. Using this approach, electrodes with up to 14.9 mg cm(-2) sulfur loading and an extremely low electrolyte/ sulfur ratio as low as 3.5: 1 mu L mg(-1) are obtained. This study sheds light on the essential role of multifaceted cathode design and further on the challenges facing lithium metal anodes in building high volumetric energy density lithium-sulfur batteries.