Complete encapsulation of sulfur through interfacial energy control of sulfur solutions for high-performance Li−S batteries

Significance Complete encapsulation of high-content sulfur into porous carbon or carbon composites is crucial for high-performance Li−S cells. However, the low-to-moderate compatibility of sulfur-dissolved solution with carbon causes difficulty in completely loading sulfur into the porous host. We control the interfacial energy of the sulfur solution by adding a solvent with high compatibility with the carbon surface. The use of NMP improves the infiltration of sulfur solution effectively, resulting in complete sulfur encapsulation. We observe that the control of sulfur loading greatly affects Li−S battery performance. We identify significantly superior cell performance in the complete encapsulation. Our method can also be applied to effectively load active materials for next-generation energy storage devices.