Flexible Array of Microsupercapacitor for Additive Energy Storage Performance Over a Large Area

An on-chip microsupercapacitor (MSC) pattern is obtained by layer-by-layer spray deposition of both manganese dioxide (MnO₂) nanoparticle-coated carbon nanotubes (MnO₂-CNTs) and MnO₂ nanosheet-decorated reduced graphene oxide (MnO₂-rGO) on mechanically robust, flexible polyethylene terephthalate. Layer-by-layer patterning of MSC electrodes offers rapid in-plane diffusion of electrolyte ions in electrodes the layered electrode and hence ultrahigh capacitance and energy density of 7.43 mF/cm² (32300 mF/cm³) and 0.66 μW h/cm² (2870 μW h/cm³), respectively, are obtained. A robust electrochemical response was measured under multiple bending of the solid-state flexible MSC as well as under repetitive cycles (∼5000).