High‐Performance All‐Printed Flexible Micro‐Supercapacitors with Hierarchical Encapsulation

Printed micro-supercapacitors (MSCs) have shown broad prospect in flexible and wearable electronics. Most of previous studies focused on printing the electrochemically active materials paying less attention to other key components like current collectors electrolytes. This study presents an all-printing strategy fabricate in-plane substrate-free MSCs with hierarchical encapsulation. new type “all-in-one” MSC is constructed by encapsulating interdigital electrodes within polyvinyl-alcohol-based hydrogel electrolyte via sequential printing. The bottom layer this fully printed helps protect device from limitation conventional substrate, showing excellent flexibility. maintain a high capacitance retention 96.84% even completely folded state. An optimal electrochemical performance can be achieved providing ample shorter transport paths for ions. using commercial activated carbon as material are endowed specific areal 1892.90 mF cm−2 at density 0.3 mA cm−2, outstanding volumetric energy 9.20 mWh cm−3 power 6.89 mW cm−3. For demonstration, thermo-hygrometer stably powered five which connected series wrapped onto glass rod. low-cost versatile believed diversify application fields