High performance nanoporous carbon microsupercapacitors generated by a solvent-free MOF-CVD method

Publication date: Available online 14 June 2019Source: CarbonAuthor(s): Yang Li, Huaqing Xie, Jing Li, Yoshio Bando, Yusuke Yamauchi, Joel HenzieAbstractMicro power sources that support high power capability, specific energy, and ultra-long cycling lifetimes are required for next generation microelectro-mechanical systems (MEMS) and miniaturized portable microdevices. We demonstrated a simple, solvent-free method to coat interdigitated electrodes with a conformal layer of porous carbon. Initially the electrodes were coated with a film of ZnO via electrodeposition to serve as the zinc source. These films were exposed to 2-methylimidazole vapor to transform the ZnO into a metal organic framework (MOF) called ZIF-8. The thickness of the ZnO film and the length of the MOF conversion process created ZIF-8 films with different morphologies, cross-sections and element compositions. The ZIF-8 films were then carbonized at 800 °C under a flowing environment of N2 gas to generate the porous carbon film electrodes for the supercapacitors. The devices have superior capacitance retention, in addition to high power and energy densities. Our 16-electrode microsupercapacitor had a stack power of 232.8 W cm−3, which could be attained even at a scan rate of 1000 V s−1, without rapid stack energy attenuation. The process of combining an inexpensive ZnO electrodeposition method with solvent-free MOF deposition and subsequent carbonization generates high surface area carbon electro...
Source: Carbon - Category: Materials Science Source Type: research