Dynamic salt capsulated synthesis of carbon materials in air

Carbonization is generally processed under an inert atmosphere to avoid the carbon oxidation at high temperatures. Here, we report a preparation method of carbon materials in air by dynamic salt capsulation. For this method, the designated two salts adopted as a reaction medium can not only ensure the stable gas release from carbon precursors, but also can create an appropriate sealing to avoid the carbon oxidation at high temperatures. Various carbon precursors can be used in this method. The yields of carbon materials by this method are close to the theoretical values in an inert atmosphere. In addition, the as-prepared thick carbon electrode with hierarchical porous structure shows better electrochemical performance than that of the commercial graphite anode. Our work provides a low-cost preparation method for carbon materials without an inert gas. The method also can be extended to other oxidation-prone materials whose precursors produce gas during calcination.