Periodic Reporting for period 1 - GRAPHERGIA (INNOVATIVE PILOT LINES FOR SUSTAINABLE GRAPHENE-BASED FLEXIBLE AND STRUCTURAL ENERGY HARVESTING AND STORAGE DEVICES)
Période du rapport: 2023-10-01 au 2025-03-31
This will lead to a scalable, cost-effective and climate-neutral production of (i) wearable e-textiles with self-powered structural sensors and (ii) next generation electrodes for Li-ion batteries. The project explores novel ideas for 2D materials engineering and integration at TRL 5 or higher, establishing versatile pilot-scale-based approaches for these applications.
Laser-scribed micro-flexible supercapacitors will be coupled to TENGs (triboelectric nanogenerators), via power management circuits acting as energy reservoirs to provide on-demand battery-less charging to wearable devices and sensors. All-in-one, self-charging power textiles with integrated electronic systems will provide a human-body-centric technology and interface of the user to the IoT by wireless transmission of sensors’ signals. In parallel, GRAPHERGIA defines a credible “dry electrode” approach to fabricate next generation electrodes for Li-ion batteries, in line with the targets of the 2030 European SET-plan. A combined 2D materials and process-oriented approaches will be adopted, based on low-cost materials and scalable approaches to ensure a cost-effective and climate-neutral production of energy harvesting/storage devices.
[1] We have developed a method capable of producing highly conductive laser-reduced graphene oxide coatings on textiles, ensuring strong adhesion of the graphene layer. Optimization is progressing to large-scale implementation, with the integration into a roll-to-roll pilot line.
[2] Trials have been performed to develop porous, high-surface-area films of graphene and graphene/nanohybrids using a single-step laser-assisted process, aiming to simultaneously form graphene and silicon nanostructures. So far, we have successfully implemented the process under ambient conditions.
[3] The design and geometry of flexible micro-supercapacitors integrated into textiles has been optimised. Graphene electrodes were fabricated using the laser-assisted process developed within GRAPHERGIA. New ionic liquid electrolytes are currently under development, with a focus on their electrochemical stability to enhance capacitance and energy storage performance.
[4] Regarding the optimization of fluoropolymer (FP) deposition via plasma-enhanced chemical vapor deposition, efforts were focused on improving FP coating quality, adhesion, durability, and washability on graphene-coated textiles. The optimized FP layer provides excellent mechanical durability without compromising the air permeability of the underlying graphene-coated fabric.
[5] Through evaluation of the performance of commercially available batteries, we defined the optimum battery design, in terms of energy performance and dimensions, specifically for very small satellite applications.
[6] Laser-processed graphene was tested for its capacity to achieve the targeted energy density. The Graphene-Si material that was produced through the laser process delivered a very promising specific capacity of over 450 mAh/g. Further investigation is underway to increase the stability of the material.
[7] A pouch cell design has been developed, to easily test any size of electrode material.
[8] A new procedure has been developed for defining the best conditioning circuit, i.e. a TENG with stable mechanical excitation and an overall system with a defined maximum voltage.
[9] We have developed a new fully automated test bench to characterize the TENG, with excellent precision, in order to extract the exact parameters of the TENG model.
[10] A new clean room process is being developed, for manufacturing miniature plasma switches based on microfabrication on silicon carbide (SiC) material.
[11] Preliminary literature reviews pertaining to eco-design of the GRAPHERGIA demonstrators have been carried out and will be gradually refined to better define the best eco-design principles to be followed. A template for eco-design data collection has been developed.
[12] Data collection for the environmental sustainability assessment of the project's processes, the life cycle inventory, the products' ecodesign, and the social life cycle assessment is under way, through dedicated templates and questionnaires.
Key advancements beyond the current state-of-the-art include:
•Development of a laser-assisted method for depositing highly conductive graphene through GO reduction on commercial and technical textiles. The method ensures strong adhesion to fibers and has reached large-scale implementation, preparing for roll-to-roll pilot-line integration and significantly advancing textile functionalization technologies.
•Establishment of a novel, single-step laser process to synthesize porous graphene/Si nanohybrids from SiC nanopowders. This binder-free approach, operating under ambient conditions, represents a paradigm shift in LIB anode technology, optimizing both conductivity and silicon activity.
•Design and electrochemical optimization of micro-flexible supercapacitors integrated onto textiles using laser-written graphene. Extensive testing is ongoing, supported by the development of next-generation ionic liquid electrolytes with wide voltage windows to enhance performance.
•Optimization of energy-harvesting fluoropolymer films deposited on graphene-coated textiles via PE-CVD, achieving excellent adhesion, long-term durability, and sustained air permeability, which are key features for scalable and reliable e-textile development.
•Performance tuning of TENG power conditioning circuits, maximizing energy conversion efficiency and compatibility with wearable applications.
•Development of a fully automated test bench, ensuring precise, repeatable characterization and performance validation across multiple device types.
Together, these innovations position GRAPHERGIA at the forefront of sustainable, scalable, and high-performance materials and systems for wearable and battery-based energy technologies.