Development of pyrolyzed nanoporous carbon electrodes with sponge-like networks of mesopores for use as supercapacitors

Abstract

We developed patternable nanoporous carbon microstructures fabricated using simple O2 plasma etching and carbon-MEMS for the application of supercapacitors. Carbon-MEMS is a versatile microfabrication technology enabling batch fabrication of micro/nano-sized carbon structure of complex architecture at a wafer level using conventional UV-lithography and pyrolysis. By incorporating a simple O2 plasma etching process prior to the pyrolysis, sponge-like nanoporous surface is formed on the top surface of pre-patterned SU-8 photoresist structures due to self-masking effect. These O2-plasma-treated photoresist structures are converted into nanoporous carbon electrodes via pyrolysis while maintaining surface morphology of sponge-like nanoporous networks. The surface area and electrochemical capacitance of the nanoporous carbon are enhanced significantly compared to a bare carbon surface. The pore size and surface morphology of the nanoporous carbon are controllable depending on O2 plasma etching time.