Väitös (konetekniikka): M.Sc., Arman Hasani

M.Sc., Arman Hasani esittää väitöskirjansa ”Advanced Characterization of Thermally Sprayed Thin-Film All-Solid-State Batteries” julkisesti tarkastettavaksi Turun yliopistossa perjantaina 20.2.2026 klo 11.00 (Turun yliopisto, Publicum, Pub3, Assistentinkatu 7, Turku).

Vastaväittäjänä toimii apulaisprofessori Heli Koivuluoto (Tampereen yliopisto) ja kustoksena apulaisprofessori Ashish Ganvir (Turun yliopisto). Tilaisuus on englanninkielinen. Väitöksen alana on konetekniikka.

Tiivistelmä väitöstutkimuksesta:

Rechargeable batteries are part of everyday life. They power our phones, laptops, medical devices, and electric vehicles. As the world moves toward cleaner energy and safer technology, there is a growing need for batteries that last longer, work more reliably, and pose fewer safety risks.

This dissertation focuses on a new type of battery called thin-film all-solid-state batteries. Unlike today’s common lithium-ion batteries, which contain flammable liquid electrolytes, these batteries use solid materials instead. This makes them much safer because they cannot leak or catch fire in the same way. Thin-film solid-state batteries are especially promising for small and emerging technologies such as sensors, medical implants, and compact electronic devices.

Despite their advantages, these batteries are still difficult and expensive to manufacture. Current production methods are slow and mainly limited to laboratory research. A major challenge is finding faster and more practical ways to make the thin ceramic layers that form the key parts of the battery.

The main goal of this research was to explore new manufacturing routes using thermal spray techniques. These techniques are already widely used in industry to coat surfaces quickly and efficiently, but they have rarely been applied to battery materials. The study focused on two critical parts of the battery: the anode, which stores lithium during charging, and the solid electrolyte, which allows lithium ions to move safely inside the battery.

One important finding is that different thermal spray methods produce very different results. Some methods preserved the battery materials well, while others caused damage, especially through the loss of lithium. These differences strongly influenced how well the battery layers could function. The research also showed that a short laser treatment after spraying can greatly improve the quality of the layers. This treatment made the coatings denser, smoother, and more uniform without overheating the entire battery.

Another important contribution of this dissertation comes the use of advanced measurement tools 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 insights into how solid-state battery materials behave during fast industrial manufacturing processes. It shows that thermal spray techniques can be used to form functional battery layers and highlights both their potential and their current limitations. By identifying which processes work best and where material damage can occur, this research offers practical guidance for future studies. The results encourage further exploration of thermal spray as a possible manufacturing route for thin-film solid-state batteries and contribute to the search for safer and more scalable battery technologies.