Next-generation paper electrodes: Linking fabrication techniques and high-performance materials for sustainable energy devices

Paper-based materials are emerging as a cutting-edge class of electroactive platforms for flexible and sustainable energy storage technologies, offering promising alternatives to conventional systems used in portable and wearable electronics. Derived primarily from cellulose, these materials exhibit exceptional mechanical flexibility, lightweight structure, tunable porosity, and rich surface chemistry, making them ideal for sustainable and high-performance electrochemical systems. This review highlights the recent progress in paper-based electrodes, focusing on two principal architectures: paper-supported and freestanding paper-like structures. Key fabrication methods, material design strategies, and electrochemical performance metrics are critically examined. Particular attention is given to paper-based supercapacitors (SCs), which offer advantages such as environmental friendliness, structural versatility, and compatibility with wearable and flexible electronics. The review further explores how advanced compositing techniques and structural engineering can significantly boost charge storage capabilities. This review examines the current challenges of mechanical resilience under stress, long-term cycling stability, and electrical conductivity, while also outlining potential future research directions. By bringing together these developments, it provides a unified framework and key insights to drive progress in green, flexible, and scalable energy storage technologies.