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/TiO 2 (cTiO 2 ), carbon/MnO 2 (cMnO 2 ), and carbon/TiO 2 /MnO 2 (cTiO 2 /MnO 2 ) 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/TiO 2 /MnO 2 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 cTiO 2, cMnO 2, and cTiO 2 /MnO 2 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/TiO 2 (cTiO 2 ), carbon/MnO 2 (cMnO 2 ), and carbon/TiO 2 /MnO 2 (cTiO 2 /MnO 2 ) composite thin films for energy storage applications.