Screen-printed electrochemically activated ink on stretchable fabric for wearable micro-supercapacitors

Abstract Micro-supercapacitors (MSCs) have received a lot of attention with the rapid development of wearable, highly integrated and flexible electronics due to their high power density and long cycle life. Among the preparation methods, the screen printing is widely used due to its simplicity, low cost, integratability and ease of industrial production. However, the conductivity, rheology and printability of the ink are still required to be further optimized in order to improve the resolution and electrochemical properties of the printed patterns. And combining high energy capacity and wearability of micro-supercapacitors is also a big challenge. Therefore, a new water-based conductive ink is prepared herein to develop CO-CNT-MnO2-based micro-electrode on stretchable cotton/spandex fabric by screen printing. The CO-CNT-MnO2/F-based MSCs with forked finger structure are further assembled combined with PVA/LiCl, which achieve an area capacitance of 8.479 mF/cm2 at 10 mV/s and reach a maximum energy density of 0.132 mWh/cm2 at the power density of 0.176 mW/cm2. In addition, the MSC still has high capacitance retention under bending/friction/tensile conditions. This work highlights the great potential of the new water-based conductive ink for application of stretchable MSCs based on screen printing.