ABSTRACT
The widespread adoption of wearable, movable, and implantable smart devices has sparked the evolution of flexible, miniaturized power supplies. High-resolution inkjet printing of flexible microsupercapacitor (µSC) electrodes is a fast, inexpensive, and waste-free alternative manufacturing technology. In this work, a 2D birnessite-type manganese dioxide (δ-MnO2) water-based ink is used to print 10-25 layers of δ-MnO2 symmetrically on a preprinted interdigitated cell consisting of 10 layers of electrochemically exfoliated graphene (EEG). The cell with 10 printed layers of δ-MnO2 achieved the highest specific capacitance, energy density, and power density of 0.44 mF cm-2, 0.045 µW h cm-2, and 0.0012 mW cm-2, respectively. Since inkjet-printing technology supports µSC manufacturing with parallel/series connectivity, four cells were used to study and improve the potential window and capacitance that can be used to construct µSC arrays as power banks. This work provides the first approach for designing an inkjet-printed interdigitated hybrid cell based on δ-MnO2@EEG that could be a versatile candidate for the large-scale production of flexible and printable electronic devices for energy storage.
