Fabrication of an all SU-8 electrospun nanofiber based supercapacitor

Supercapacitors (SCs) as energy storage devices are advantageous in their rapid charge/discharge capabilities and their immense charge storage capacity. Two important components of a SC are the electrically conductive electrodes (anode and cathode) and an electrically non-conductive separator between the two electrodes. This paper details a fabrication process for nanofibrous carbon electrodes and a nanoporous polymer separator using all SU-8 based electrospinning and post electrospinning processes, such as lithographical patterning, conversion of the nanofibrous polymer to carbon structures using heat treatment (carbonization) and their assembly to complete a SC. The process produces immensely porous electrodes with good conductivity; it is scalable and economical compared with the carbon nanotube electrode approach. High throughput tube nozzle electrospinning for nanofiber (NF) production and its photolithographical patterning have been employed to facilitate manufacturability. The dependence of the NF morphology on the carbonization temperatures is studied. Also, SC testing and characterization are discussed.