Recycling Of Laminar Materials Used In Energy Storage Devices

<p dir="ltr">This thesis introduces novel recycling approaches for spent and production scrap of laminar energy storage materials, with a focus on lithium iron phosphate (LFP) cathode and catalyst-coated membranes (CCMs) used in the fuel cell and water electrolyser. The main objective is to develop efficient, environmentally friendly, and economically viable methods for recovering valuable materials from these end-of-life components and production scraps, thereby contributing to a sustainable and circular economy for energy storage technologies. For LFP cathodes, a novel direct re-lithiation strategy was investigated, utilising a lithium-based eutectic system and an organic reducing agent. This approach offers a simple, low-temperature, and energy-efficient method for regenerating the spent LFP cathode material without requiring complex chemical processes. The eutectic system provides a suitable medium containing excess lithium ions, facilitating diffusion and intercalation, while the reducing agent facilitates the reduction of iron ions to regenerate LFP cathode material, restoring its electrochemical performance. Innovative techniques were investigated regarding the production of scrap CCM recycling. A two-step process involving organic solution soaking and insonation in water with an ultrasonic bath in a short period demonstrated effective delamination of the catalyst layers from the membranes, conserving both components (active material and membrane) for further recovery. Pre-soaking CCMs with an organic solution is found to play a vital role in rapidly removing active catalytic particles; this is likely due to a change in the ionomer structure of the particle-loaded ionomer film. The ultrasonication disrupts the remaining interfacial forces that bind the active materials to the membrane. This approach offers a gentle and controlled method for separating the components of the CCMs without damaging their structural integrity. Additionally, high-intensity ultrasonication was employed to achieve rapid and efficient delamination of the fuel cell CCM at ambient temperature, enabling a scalable and continuous recycling process. The high-intensity sound waves generated by the sonotrode create cavitation bubbles that collapse, producing high-speed jets and shockwaves that disrupt the interfacial bonds between the catalyst layers and the membrane. This technique offers a fast and efficient way to recycle large quantities of production scrap CCM sheets, making it suitable for industrial-scale applications. The findings presented in this thesis contribute to developing sustainable and circular economy solutions for recycling laminar energy storage materials. They offer practical and promising directions for recovering valuable materials from spent and production scrap laminar energy storage materials, addressing the growing demand for critical materials, and reducing the environmental impact of energy storage material waste. This research introduces confidence in the practicability of a more sustainable and resource-efficient energy storage industry.</p>