Characterization of Inkjet-Printed Stacked MIM Thin-film Solid-State Flexible Super-Capacitor

Abstract

Electrical energy storage need has evolved to lightweight and portable devices such as electric vehicle, drones, robotics, wearables, etc. Current technology of batteries such as Li-Ion or Li-Poly are not able to meet the requirement for future. We have been developing a new type of supercapacitor for this technological barrier. Our supercapacitors are fabricated with inkjet-printing (IJP) technique that uses very precise MEMS based cartridge to print thin-films on planar substrates. We have previously demonstrated metal-insulator-metal (MIM) capacitor fabrication and simulation, as well as stacked MIM supercapacitor fabrication. In this paper, we present electrical characterization (such as charging-discharging cycles) and scanning electron microscopy image for IJP stacked MIM supercapacitor. The electrical characterization validates the charge storage capability of the supercapacitor. We have tested the samples for up to 20 V charging voltage. The corresponding stored charge can be as high as 40 nC, and the charge density is 17.4 $\mathbf{C}/\mathbf{m}^{3}$. These solid-state IJP stacked MIM supercapacitors are flexible with high energy-density and safe for prolonged use which can be applicable in electric vehicles, wearables, implantable, drones, and other energy storage applications.