Sulfur-Tuned Advanced Carbons of Novel Properties and Scalable Productivity

Abstract

Sulfur-tuned advanced carbons (STACs) with high mass loadings of sulfur are synthesized using an environmentally benign and scalable steam-assisted sulfur insertion (SASI) method. While steam provides the pressure necessary to promote deep and rapid sulfur insertion into a carbon porous structure, a strong affinity between melted sulfur and carbon excludes water from pore penetration. The resulting STACs exhibit sulfur mass loadings up to 85% and the electrical conductivity of the carbon framework is largely preserved. The sulfur penetration can be tuned to fill specific pore sizes, enabling pore-size-dependent allocation of sulfur and controllable porosity, while sulfur lines the carbon pore surfaces. A significant amount of sulfur is in the monoclinic γ phase. To demonstrate their energy and environmental applications, the STACs are used as cathode materials in rechargeable aluminum-sulfur batteries and as adsorption materials for spilled oil removal.