Mechanically Stable Carbide Derived Carbon Nanoporous Films for Micro-Supercapacitors

Integration of electrochemical capacitors with silicon-based electronics is a major challenge, limiting energy storage on a chip. Here it will be presented the electrochemical behavior of micro-supercapacitors achieved of strongly adhering carbide-derived carbon films obtained from TiC conversion through a process compatible with current microfabrication and silicon-based device technology. By playing around chloration temperature, electrochemical properties are easily tunable, then capacitance of those films reaches 410 farads per cubic centimeter/200 millifarads per square centimeter in aqueous electrolyte and 170 farads per cubic centimeter/85 millifarads per square centimeter in organic electrolyte. With a maximum areal power and energy of 100 milliwatts per square centimeter and 19 microwatthours per square centimeter, for a 2 micrometers thick film, such achieved carbon layers outperform today's microsupercapacitor state of the art. What's more, those carbon films exhibit an excellent mechanical stability since a Young's modulus of 14.5 gigapascals is measured enabling the preparation of self-supported, mechanically stable, micrometer-thick porous carbon. So further transfer onto flexible substrates is feasible and it is demonstrated that carbon free standing films can exhibit a volumetric capacitance as high as 400 farads per cubic centimeter. These materials are interesting for applications in structural energy storage, tribology, and gas separation.