Conducting polymer ink for flexible and printable micro-supercapacitors with greatly-enhanced rate capability

Conducting polymer ink holds great promise for wearable, flexible, and printable high-power-density micro-supercapacitors (MSCs) but chronically suffers from the poor rate capability ascribing to naturally electron-blocked transferring. Herein, we devise an air-stable, easy-fabricating and rapid electron-transferring polyaniline ink by embedding conductive carboxylic multi-walled carbon nanotubes (C-MWCNTs) networks into polyaniline nanosheets. Due to the optimized electron-transferring kinetics, the rate capability of polyaniline ink is significantly increased by 73.7%. Additionally, the large-scale printable MSCs based on this ink deliver remarkable energy density of 2.6 mWh cm−3, large areal capacitance of 45.4 mF cm−2 and excellent mechanics-electrochemistry stability with 84.6% capacitance retention against 1000 consecutive bending cycles. Evidently, this work provides the polyaniline ink for large-scale, printable, and flexible MSCs, which can underpin the next generation printed electronics in the approaching era of Internet of Things.