Toward Green Electronics: Screen-Printed MXene-Based Microsupercapacitors on Paper Substrate with Nafion-Based Gel Electrolyte

The rise of electronic waste worldwide over the years has given birth to a new field of research of sustainable, biodegradable, green electronics, which generate minimal waste with less carbon emission. A sustainable platform for continuous sensor monitoring in wearable electronics requires a sustainable, clean, safe, and flexible energy storage solution. Research on paper electronics has seen a major flourishing in recent years, where the need of the hour is to find a sustainable energy storage solution. Recently discovered, MXene electrodes typically use H2SO4-based electrolytes, which are quite toxic and harmful. In this work, as an alternative, a novel Nafion-based gel electrolyte has been developed, operating within the same potential window as H2SO4 (0.6 V). This screen-printed, biocompatible MSC on paper substrates has an outstanding capacitance of 121 mF cm-2 at a voltage scan rate of 1 mV s-1, with only a single pass of screen printing. This strategy provides stable, inexpensive, environment-friendly, scalable, and flexible on-chip micro-supercapacitors, paving the way for a next-generation energy storage platform for wearable electronics.