In my master’s thesis, I explore Prussian blue as a safe-and-sustainable-by-design cathode material for sodium-ion batteries, an emerging alternative to conventional lithium-ion batteries. As the global transition to renewable energy accelerates, the demand for efficient energy storage is rapidly increasing. However, lithium-ion batteries rely on scarce and often toxic materials such as lithium, cobalt, nickel, and manganese, which pose environmental, social, and health risks and face growing supply constraints.

Sodium-ion batteries offer a promising alternative, as sodium is abundant and affordable, and Prussian blue analogues can be synthesized from non-toxic, earth-abundant elements through a simple and low-cost process. While these materials show strong electrochemical potential, their safety—particularly for vulnerable populations such as unborn children—has not yet been fully assessed.

In my research, I therefore adopted a safe-by-design approach, evaluating battery performance and toxicity simultaneously during the material design phase. I synthesized thirteen Prussian blue samples under controlled conditions, varying parameters such as temperature and atmosphere. These materials were characterized and tested for electrochemical performance as well as developmental toxicity using stem cell models.

The results demonstrate that careful tuning of synthesis parameters makes it possible to optimize battery performance while keeping toxicity low. This confirms that safety and sustainability do not need to be sacrificed for technological efficiency, and that sodium-ion batteries with Prussian blue cathodes hold strong potential for future energy storage solutions.

With my thesis, I contribute to sustainability by developing a safe-and-sustainable-by-design approach to next-generation battery materials. Rather than optimizing performance first and addressing health and environmental risks later, I demonstrate that safety, sustainability, and performance can be integrated from the earliest stages of material development.

Ecologically, my research supports the transition away from lithium-ion batteries that rely on scarce, toxic, and environmentally damaging raw materials. By using abundant and non-toxic elements, sodium-ion batteries with Prussian blue cathodes reduce environmental pollution and resource dependency. Economically, the materials are cost-effective and scalable, making sustainable energy storage more accessible. Socially, avoiding critical and conflict-prone metals helps reduce geopolitical tensions and unsafe labor conditions associated with current battery supply chains.

By combining chemistry, environmental health sciences, and biomedical testing, my work provides an interdisciplinary framework that can guide future battery innovation. In particular, the focus on developmental toxicity ensures that the energy transition does not come at the expense of human health or future generations.

Overall, my thesis shows that truly sustainable technologies are those that balance environmental responsibility, social justice, and technological performance, offering concrete insights for a safer and more resilient energy future.