Paper‐Based Printed Supercapacitor Loaded With Carbon Black and Gold Nanoparticles for Sustainable Energy Storage Devices

Flexible supercapacitors (FSC) are revolutionizing smart wearable and implantable electronic devices, offering excellent mechanical flexibility and outstanding energy and power densities. In this work, we report a new sustainable paper‐based FSC which consists of a paper substrate loaded with graphite ink, carbon black, and gold nanoparticles sandwiched with a solid‐state electrolyte. The materials are deposited on a paper‐based substrate, thus establishing a novel approach to eco‐friendly, high‐performance FSC. The prepared materials and FSCs were morphologically and electrochemically characterized by scanning electron microscopy, electrochemical impedance spectroscopy, cyclic voltammetry, and galvanostatic charge–discharge tests. When the weight ratio of graphite ink/carbon black/gold nanoparticles is adjusted to 93 wt%/5 wt%/2 wt%, respectively, the resulting FSC exhibits the optimal electrochemical performances demonstrated by: (i) specific capacitance of 154 mF/cm 2 , (ii) energy density of 0.013 mWh/cm 2 , (iii) power density of 6.5 mW/cm 2 , and (iv) extended cycling stability of 85% after 10 000 cycles. This work highlights the significant role of standard office paper for the suitable contribution to develop flexible and sustainable electrochemical energy storage devices in advancing the functionality and autonomy of current and future portable and wearable electronics systems, paving the way for large‐scale production of cost‐effective and flexible printed devices.