A Simple Strategy towards Highly Conductive Silver-Nanowire Inks for Screen-Printed Flexible Transparent Conductive Films and Wearable Energy-Storage Devices

Printable silver-nanowire (Ag NW) inks with simple formulation, low cost, and high conductivity are developed and screen printed on flexible poly(ethylene terephthalate) substrates. By using ultralong Ag NWs (≈75 µm in length) as the conductor, the screen-printed Ag NW patterns exhibit exceptional conductivity (up to 8.32 × 10³ S cm⁻¹) and excellent mechanical robustness. Rheological behavior suitable for screen printing is achieved by adjusting the formulation of the inks, which assures neat and smooth screen-printed lines with resolution as high as 100 µm. Uniform and honeycomb-structured Ag NW transparent conductive films with superior flexibility and optical transmittance ≈80% are obtained by screen printing the Ag NW inks. Flexible all-solid-state supercapacitors based on Ag NW/PEDOT:PSS electrodes reach areal specific capacitance as high as 8.58 mF cm⁻², a value threefold higher than that of pristine PEDOT:PSS electrodes. Moreover, a high flexibility with a bending angle of 180° and long-term stability with ≈90% capacitance retention over 2500 cycles, is also obtained, manifesting this material's great potential applications for flexible and wearable energy-storage devices.