Printing 3D Array of Electrodes Made of Graphene/Carbon Black for Microsupercapacitors

Microsupercapacitors are important power suppliers for microelectronics, but their application is limited by low charge storage ability. Increasing the active material loading in the electrode can not only enhance charge storage ability but also increase the thickness of the electrode, which suffers from limited electrolyte ion diffusion. In this study, we design and print a 3D array-structured graphene/conductive carbon black electrode featuring tailored porosity and electrical conductivity via a self-sacrifice template of ethyl cellulose and carbon black. This structure design of electrode enhances active material sufficiency utilization with good electrode and electrolyte contact and facilitates electrolyte ion diffusion into the electrode. Their synergistic effect significantly improves the electrochemical performance of the microsupercapacitor, including a high areal capacitance of 35.75 mF cm^–2, areal energy of 27.71 μWh cm^–2, and power densities of 1.10 mW cm^–2. A single device can power a pressure sensor for over 10,000 s, highlighting its remarkable potential for practical applications. This work would be beneficial for the development of microsupercapacitors.