Flexible Planar Microsupercapacitors Based on Polypyrrole Nanotubes

As miniaturized energy storage devices, flexible planar microsupercapacitors (MSCs) with high performance have broad applications on flexible electronics. However, traditional electrode fabrication methods (photolithography, laser writing, inkjet printing, etc.) are complex and expensive. In this work, a patterned interdigital electrode, which was prepared with a hard template of hydrophobic glue paper, was proposed. Peelable nickel nanocone arrays (NNAs) and polypyrrole nanotubes (PPyNTs) were electrochemically deposited on the substrate as 3D conductive frames and active material, respectively. The device demonstrates an areal capacitance up to 60.2 mF cm–2, high capacitance retention of 84.3% after 5000 cycles, as well as impressive mechanical performance that can work after 180° bending. Furthermore, a high energy density of 5.35 μWh cm–2 and power density of 2 mW cm–2 were obtained. Lastly, the fabricated MSCs presented great potential to integrate with series and parallel