Fabrication of an environmentally-friendly PEDOT:PSS/MoS2 composite ink for the application of inkjet-printed high-performance flexible micro-supercapacitors

The prosperity of flexible and wearable electronic devices stimulates the increasing demand for high flexibility and miniaturization of energy storage devices. Inkjet printing allows rapid, low-cost, and precise large-scale production of flexible electronics, and injects new blood into the fabrication technology community. The synergistic coupling effect of Poly (3,4-ethylenedioxythiophene): Poly (styrenesulfonate) (PEDOT:PSS) and molybdenum disulfide (MoS 2 ) brings possibility to enhance the performance of micro-supercapacitors (MSCs). In this work, for the first time an aqueous and non-toxic printable PEDOT:PSS/MoS 2 composite ink is prepared for inkjet printing of paper-based MSCs. The influences of composite ratio of inks and electrode thickness on the device performance are detailedly explored, and the optimized parameters are uncovered. The maximum areal capacitance for the printed MSCs could reach 1.572 mF/cm 2 , and maintain 97.4 % of capacity at high current densities (60 μA/cm 2 ), and the maximum areal energy density could reach 0.22 μWh/cm 2 under a power density of 4.97 μW/cm 2 , indicating great potential for the applications on wearable energy storage systems.