On 2 October 2026, Fernanda Monteiro Freitas defended her PhD thesis, “Phosphate-Based Materials for All-Solid-State Thin-Film Lithium Batteries”, in the PhD Programme in Materials Science of the Universitat Autònoma de Barcelona (UAB).
Thin-film batteries are only a few micrometres thick and are built layer by layer, directly on a chip. They can power small devices such as sensors, wearable electronics and Internet-of-Things nodes. Using a solid instead of a liquid electrolyte makes them safer, and research is now looking for alternatives to the current benchmark materials that are also more sustainable.
Fernanda worked with two phosphate materials: lithium iron phosphate (LFP) as the positive electrode, and the ceramic Li1+xAlxTi2–x(PO4)3 (LATP) as the solid electrolyte. She studied how deposition conditions, interfaces and heat treatments control the structure and electrochemical behaviour of the films. She then assembled complete batteries, confirming that the LFP films work as electrodes.
The thesis also pinpoints the main remaining hurdles – interfaces, crystallisation of the electrolyte, mechanical integrity and compatibility between electrode and electrolyte – and gives practical guidelines for safer, more sustainable microbatteries.
Congratulations, Fernanda!
