Improved conductivity and capacitance of interdigital carbon microelectrodes through integration with carbon nanotubes for micro-supercapacitors

In the last decade, pyrolyzed-carbon-based composites have attracted much attention for their applications in micro-supercapacitors. Although various methods have been investigated to improve the performance of pyrolyzed carbons, such as conductivity, energy storage density and cycling performance, effective methods for the integration and mass-production of pyrolyzed-carbon-based composites on a large scale are lacking. Here, we report the development of an optimized photolithographic technique for the fine micropatterning of photoresist/chitosan-coated carbon nanotube (CHIT-CNT) composite. After subsequent pyrolysis, the fabricated carbon/CHIT-CNT microelectrode-based micro-supercapacitor has a high capacitance (6.09 mF·cm^–2) and energy density (4.5 mWh·cm^–3) at a scan rate of 10 mV·s^–1. Additionally, the micro-supercapacitor has a remarkable long-term cyclability, with 99.9% capacitance retention after 10, 000 cyclic voltammetry cycles. This design and microfabrication process allow the application of carbon microelectromechanical system (C-MEMS)-based micro-supercapacitors due to their high potential for enhancing the mechanical and electrochemical performance of micro-supercapacitors.