Dissertation defence (Mechanical and Materials Engineering): M.Sc., Arman Hasani

M.Sc., Arman Hasani defends the dissertation in Mechanical and Materials Engineering titled “Advanced Characterization of Thermally Sprayed Thin-Film All-Solid-State Batteries” at the University of Turku on 20 February 2026 at 11.00 (University of Turku, Publicum, Pub3, Assistentinkatu 7, Turku).

Opponent: Associate Professor Heli Koivuluoto (Tampere University, Finland)

Custos: Associate Professor Ashish Ganvir (University of Turku)

Summary of the Doctoral Dissertation:

Rechargeable batteries are everywhere in modern life, from mobile phones and medical devices to electric vehicles and renewable energy systems. As society moves toward cleaner and safer energy solutions, there is a growing need for batteries that are not only powerful but also safer, longer-lasting, and easier to manufacture. This dissertation focuses on a new type of battery known as thin-film all-solid-state batteries, which replace the flammable liquid found in today’s batteries with solid materials.

All-solid-state batteries are considered much safer because they cannot leak or catch fire in the same way as conventional lithium-ion batteries. Thin-film versions of these batteries are especially attractive for small and emerging technologies, such as sensors, medical implants, and compact electronic devices. However, producing these batteries is currently slow, complex, and expensive, which limits their wider use outside research laboratories.

The key aim of this research was to explore faster and more scalable ways to manufacture the ceramic layers used in thin-film solid-state batteries. The dissertation investigates thermal spray techniques, which are widely used in industry to coat surfaces quickly and efficiently. These methods have rarely been applied to battery materials before. The work focuses on two important battery components: the anode, which stores lithium during charging, and the solid electrolyte, which allows lithium ions to move safely inside the battery.

One of the main findings of the research is that different thermal spray methods produce very different results. Some processes were able to preserve the desired battery material much better than others, while certain methods caused damage to the material, especially through the loss of lithium. These differences strongly affected how well the battery layers could function. The research also showed that a short laser treatment after spraying can significantly improve the quality of the battery layers by making them denser, smoother, and more uniform, without overheating the entire device.

Another important contribution of this dissertation is the use of advanced measurement techniques available at synchrotron research facilities. These tools made it possible to look inside the battery layers in great detail and reveal changes that cannot be seen with standard laboratory equipment. This allowed the research to clearly link manufacturing methods to material quality and battery performance.

Overall, this work provides new knowledge on how solid-state battery materials behave during fast industrial manufacturing processes. It shows that thermal spraying, combined with laser treatment, has strong potential as a practical and scalable route for producing thin-film solid-state batteries. The results help bridge the gap between laboratory research and real-world battery production and support the development of safer and more reliable energy storage technologies for future applications.