Air‐Stable Conductive Polymer Ink for Printed Wearable Micro‐Supercapacitors

Printed electronics are expected to facilitate the widespread distributed wearable electronics in the era of the Internet of things. However, developing cheap and stable electrode inks remains a significant challenge in the printed electronics industry and academic community. Here, overcoming the weak hydrophilicity of polyaniline, a low‐cost, easy‐fabricating, and air‐stable conducting polymer (CP) ink is devised through a facile assemble‐disperse strategy delivering a high conductivity in the order of 10−2 S cm−1 along with a remarkable specific capacitance of 386.9 F g−1 at 0.5 A g−1 (dehydrated state). The additive‐free CP ink is directly employed to print wearable micro‐supercapacitors (MSCs) via the spray‐coating method, which deliver a high areal capacitance (96.6 mF cm−2) and volumetric capacitance (26.0 F cm−3), outperforming most state‐of‐the‐art CP‐based supercapacitors. This work paves a new approach for achieving scalable MSCs, thus rendering a cost‐effective, environmentally friendly, and pervasive energy solution for next‐generation distributed electronics.