Screen-printed water-based conductive ink on stretchable fabric for wearable micro-supercapacitor

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, 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 a high energy capacity and wearability of MSCs is also a big challenge. Therefore, a green and environmentally friendly water-based conductive ink is prepared herein to develop a CO-CNT-MnO2-based micro-electrode on stretchable cotton/spandex fabric by screen printing. The CO-CNT-MnO2/F-based MSCs with a forked finger structure are further assembled combined with PVA/LiCl, and high electrochemical performance of the assembled device due to the synergy of double layer capacitance and pseudocapacitor capacitance storage could be achieved as an area capacitance of 8.479 mF/cm2 at 10 mV/s and reach maximum energy density of 0.132 mWh/cm2 at power density of 0.176 mW/cm2. In addition, the assembled MSCs still have high capacitance retention under stretching/folding/bending/friction conditions. This work highlights the great potential of the new water-based conductive ink for the application of stretchable MSCs based on screen printing.