Polystyrene‐MOF‐Derived 3D Hierarchical Porous Carbon for High‐Performance Supercapacitors

The ability to tailor surface area, porosity, and morphologies has driven extensive research into the synthesis of metal-organic frameworks derived carbons and their applications in energy storage. This study presents the development of three-dimensional hierarchically porous carbon derived from polystyrene and small-sized zeolitic imidazolate framework-8 (ZIF-8) particles. Incorporating nanometer-sized ZIF-8 particles forms a core-shell structure in the pre-carbonization stage, transforming into a porous carbon material with a range of pores from micro to macropores after carbonization. The carbonized material's electrode demonstrates a high capacitance of 428.8 F g^-1 at 1 mV s^-1 in the three-electrode setup and a very high specific energy of 48.75 Wh kg^-1 at 50 mA g^-1 in the packed flat cell configuration. This exceptional electrochemical performance is attributed to the composite carbon material's high surface area, well-developed pore structure, and self-doped nitrogen content.