Paper with Power: Engraving 2D Materials on 3D Structures for Printed, High‐Performance, Binder‐Free, and All‐Solid‐State Supercapacitors

Abstract The prevalence of the Internet of Things (IoT) and wearable electronics create an unprecedented demand for new power sources which are low cost, high performance, and flexible in many application settings. In this paper, a strategy for the scalable fabrication of high‐performance, all‐solid‐state supercapacitors (SCs) is demonstrated using conventional paper and an inkjet printer. Emerging printed electronics technology and low‐cost chemical engraving methods are bridged for the first time to construct Cu_xO nanosheets, in situ, on the 3D metallized fiber structures. Benefitting from both the “2D Materials on 3D Structures” design and the binder‐free nature of the fabricated electrodes, substantial improvements to electrical conductivity, aerial capacitance, and electrochemical performance of the resulting SCs are observed. With the proposed strategy, the fabricated SCs can be seamlessly integrated into any printed circuit, sensors, or artwork; the properties of these SCs can be easily tuned by simple pattern design, fulfilling the increasing demand of highly customized power systems in the IoT and flexible/wearable electronics industries.