TOPIC #5
Designing Next-Generation Electrolytes for Sodium-Ion Batteries: New Materials for NaPF6 Stabilization and the Replacement of Carbonate-Based Systems
Research area: Post Li-Ion Technologies, New Materials & Electrolytes,
Keywords: Na-ion batteries; Na salts; Electrolyte; Beyond carbonates
Supervising team: Eduardo SANCHEZ (CIC EnergiGUNE) & Patrik JOHANSSON (Uppsala Univ.)
Abstract
This PhD project aims to explore novel electrolyte formulations for high-voltage sodium-ion batteries (SIBs). The research will integrate cutting-edge interphase characterization techniques—combining physicochemical methods such as X-ray Photoelectron Spectroscopy (XPS) with advanced electrochemical testing—and predictive models to elucidate the mechanisms governing electrode–electrolyte interphase formation. The project will focus on discovering new sodium salts and incorporating innovative components into electrolytes to replace or stabilize the current NaPF₆-based carbonate solutions. Presently, these formulations suffer from limited chemical and thermal stability, primarily due to the high reactivity of NaPF₆ and the volatility of carbonates. Sodium-ion batteries are considered strong candidates to meet the growing demand for energy storage, both for stationary and mobility applications, addressing the challenges posed by limited lithium resources. The anticipated outcomes of this research are expected to have a significant impact on the field, contributing to the development of safe, scalable, and post-lithium solutions. Specifically, it is expected that the new electrolytes will improve cyclability by enhancing compatibility with hard carbon anodes and high-voltage sodium cathodes.
Interest for the student
Expected mobility: As part of the dissemination activities for this research, the ESR will present their findings at both national and international conferences (e.g., those organized by the Materials and Electrochemical Research Societies, the Post-Lithium Storage Cluster of Excellence, etc.). Additionally, the ESR will participate in specialized training workshops focusing on experimental techniques (e.g., the Instrumental Methods in Electrochemistry course as part of the Southampton Electrochemistry Summer School) and computational methods (DTU BATMAN school and Oxford Battery Modelling School). Furthermore, the ESR will undertake a 6-month secondment in the group of Prof. Patrik Johansson at Uppsala University, where they will gain expertise in applying density functional theory (DFT) to calculate dissociation energies, electrochemical stability, and the solubility of the developed components in the electrolyte and interphase.
Career opportunities: The ESR will undergo cross-disciplinary training in cutting-edge areas of materials science, significantly enhancing their scientific profile and professional development, thereby opening up diverse career opportunities. The research team offers a unique opportunity to combine advanced materials synthesis with sophisticated interphase characterization, supported by computational chemistry, providing exceptional access to training, facilities, and expertise. Specifically, the ESR will have access to state-of-the-art infrastructures and collaborate with renowned research groups, which will greatly contribute to their professional growth and employability. This research opportunity is expected to positively impact not only the scientific outcomes but also the educational experience of the ESR. In addition to technical skills, the ESR will develop key competencies for career success, including teamwork, supervision of undergraduate students, and effective communication of research findings. Active participation in dissemination activities will be strongly encouraged, including internal seminars, international and national conferences, workshops, and outreach events such as Openlab days, facilitating interaction with potential future employers and stakeholders. Moreover, the ESR will have access to internal training on soft skills provided by external experts (e.g., communication, time management, scientific writing, funding acquisition), as well as language courses (Spanish for non-Spanish speakers, English, and Basque) as part of our comprehensive training program. Given these extensive training and development opportunities, we anticipate that the ESR will be highly employable in both industry and academia.
