Laser printer patterned sacrificed layer for arbitrary design and scalable fabrication of the all-solid-state interdigitated in-planar hydrous ruthenium oxide flexible micro supercapacitors

We demonstrate the successful fabrication of all-solid-state flexible micro-supercapacitors (μSCs) on commercial polyethylene terephthalate (PET) sheet using a commercial laser printer. The interdigitated in-planar electrodes of the μSC are fabricated by commercial toner cartridge and their self-aligned stacking configurations are made by depositing Pt thin films and hydrous ruthenium oxide (RuO·xH2O, hRuO2) layers on the PET sheets using a post-low-temperature annealing process. The μSC cells can be combined in parallel or series by an arbitrary printing process operated on a personal computer, thereby avoiding unnecessary external connections and improving the capacitive behavior. The fabricated hRuO2-based μSCs exhibit excellent electrochemical-energy storage, along with ultrahigh volumetric power density (73460 mW cm−3) and energy density (24.9 mWh cm−3). This facile and simplified strategy constructs μSCs with tailored self-aligned electrodes of arbitrary design, excellent mechanical stability, and high flexibility. Therefore, it offers a high-productivity, low-cost, photolithography-free microfabrication of μSCs for microscale supercapacitor applications.