Week 4 focused on the critical role of raw materials in lithium battery formulations, emphasizing the significance of recycling processes and the principles of circularity. The session explored how the sustainability of batteries is intricately linked to the management of these materials, which are essential for meeting the growing demand for energy storage. It highlighted innovative recycling techniques that aim to recover valuable components from spent batteries, thereby reducing waste and environmental impact. The concept of circularity was dissected to illustrate how a closed-loop approach can maximize resource efficiency and minimize the reliance on virgin materials. Overall, the discussions underscored the urgent need for sustainable practices in the battery life cycle, facilitating a transition towards greener technologies in the energy sector.