Metal-Oxide Decorated Multilayered Three-Dimensional (3D) Porous Carbon Thin Films for Supercapacitor Electrodes

We demonstrate an easy, scalable, and two-step synthesis of macroporous carbon, carbon/TiO₂ (cTiO₂), carbon/MnO₂ (cMnO₂), and carbon/TiO₂/MnO₂ (cTiO₂/MnO₂) composite thin films for energy storage applications. The direct synthesis of the hybrid films was achieved by spin coating, followed by carbonization. The unique multilayered three-dimensional (3D) pore structure of the film permits the synthesis of carbon/TiO₂/MnO₂ nanocomposites with enhanced metal-oxide nanoparticle loading up to 50 wt %. The as-synthesized porous carbon thin films were tested for their supercapacitor activity and a maximum specific capacitance ∼44 F g^-1 was achieved with a film thickness of 350 nm. The as-prepared cTiO₂, cMnO₂, and cTiO₂/MnO₂ electrodes exhibit high specific capacitances of 178, 237, and 297 F g^-1, respectively, at 5 mV s^-1, because of their unique properties with impregnated nanoparticles, and direct fabrication on conductive substrates. This simple scalable coating technique is compatible with the high-speed roll-to-roll manufacturing processes and easily generalized for other carbon/metal oxide composites. We demonstrate an easy, scalable, two-step synthesis method similar to the roll-to-roll process for the synthesis of multilayered of macroporous carbon, carbon/TiO₂ (cTiO₂), carbon/MnO₂ (cMnO₂), and carbon/TiO₂/MnO₂ (cTiO₂/MnO₂) composite thin films for energy storage applications. (Graph Presented).