Fully printed energy storage devices on consumer paper substrates: an eco-friendly approach for a low-cost and disposable smart electronics system

The integration of electronic devices into wearable applications has revolutionized the way we interact with technology. The utilization of sustainable materials that align with the principles of environmental consciousness makes it more remarkable. In this context, we propose the fabrication of an energy storage device, a supercapacitor, prepared following a “green approach”, starting from the substrate used for its fabrication, i.e., various paper-based materials, and continuing through to the final step. The device fabrication was achieved through screen printing, a scalable and efficient technique that enables precise deposition of materials while eliminating waste. The electrode component is carbon-based, offering cost-effectiveness and mechanical durability, while the use of sodium alginate as both the electrolyte and the interlayer represents a significant innovation. By playing a dual role, sodium alginate reduces the need for additional materials, simplifying the manufacturing process and lowering the device's overall environmental impact. Sodium alginate, derived from renewable and sustainable sources, possesses exceptional biocompatibility and eco-friendliness. Its high ion conductivity and excellent film-forming capabilities make it particularly well-suited for flexible and wearable electronic devices. The power of the obtained interdigitated supercapacitor ranged between ∼880 µW kg⁻¹ and 505 mW kg⁻¹. This approach not only optimizes the device structure but also reduces its ecological footprint, aligning with the growing demand for low-cost green energy technologies and sustainable materials in electronic applications.