Fabrication and tests of a three-dimensional microsupercapacitor using SU-8 photoresist as the separator

Presented is a microsupercapacitor using SU-8 photoresist as the separator, featuring by high-aspect-ratio three-dimensional (3D) electrodes and high capacity per unit area. A scalable and mechanically stable structure for microsupercapacitors has been designed. By combining the preparation strategy for self-supporting nanoporous electrodes with micromachining technologies for high-aspect-ratio structures, 3D electrodes that allow for a heavy load of electrode material per unit area has been achieved. Electrochemical characterisation results of the prototype using ionic liquid as the electrolyte demonstrate that the microsupercapacitor exhibits a high specific energy of 330 mJcm^-2 and a large specific capacitance of 160 mFcm^-2, which are attributed to both the high-performance materials and the well-designed microstructure. This device can be potentially applied to various energy systems, such as electronic backup power supplies and microenergy storage devices.