Optimization of Micro-Scale Organic Energy Storage Devices

Abstract

In pseudo-capacitors the energy storage process is due to fast, reversible faradic processes. For their higher specific capacitance with respect to conventional electrical double-layer capacitors that make use of high surface area carbons, these devices are among the most promising to provide high energy density and power necessary for modern and future applications. But the era of searching only for the best performance leaving environmental concerns is in the past: and now we have the moral obligation and responsibility of making every new technology evolving into sustainable and eco-friendly alternatives. Our group has achieved binder-free eco-friendly organic supercapacitors on different substrates such as carbon paper and polyethylene terephthalate (PET), using drop casting and microfabrication techniques, obtaining a specific capacitance of 167 Fg-1 on carbon paper, and 10.8 Fg-1 on flexible PET [1]. In this work we optimize the microfabricated structure of flexible melanin-based electrodes by modifying the geometric architecture, maximizing the electrode/electrolyte interaction. Specifically, we report about the energy storage of flexible melanin-based micro-capacitors in aqueous electrolytes (NH4CH3COO(aq)). References [1] Prajwal Kumar, Eduardo Di Mauro, Shiming Zhang, Alessandro Pezzella, Francesca Soavi, Clara Santato, Fabio Cicoira."Melanin-based flexible supercapacitors". J. Mater. Chem. C, 2016, 4, 9516.