TOPIC 04 - Beyond iron and manganese: toward 4 V Prussian Blue Analogue cathode materials for Sodium-ion batteries

This PhD project aims at providing high-quality and multidisciplinary training on high-voltage cathode materials development using a twofold synergistic approach: (1) state-of-the-art experimental synthesis and characterization; and (2) high-throughput platforms. The research project objective is to unlock the reversible extraction of two sodiums in high voltage Prussian Blue Analogue compounds Na2-δM[Fe(CN)6], M = transition metal, which is a joint and complementary collaboration between CIC energiGUNE (Spain) and Institut Charles Gerhardt
Montpellier (France).

The experimental approach will be based on the optimization of materials’ structural-chemical properties using CIC energiGUNE’s new highthroughput automated synthesis setup combined with the use of a broad range of characterization techniques (ICP, TGA-MS, EA, XRD, SEM, HRTEM, magnetometry, ssNMR, etc…) and state of the art electrochemical testing lab for galvanostatic cycling, cyclic voltammetry, PITT/GITT and impedance spectroscopy. This will be complemented by Mössbauer spectroscopy experiments at Institut Charles Gerhardt Montpellier, allowing to determine the iron oxidation state and its structural environment. Mechanistic insight will then be monitored and studied through the use of operando techniques, such as PXRD at CIC energiGUNE, Mössbauer at Institut Charles Gerhardt Montpellier, and XAS at synchrotron facilities. Special focus will be made on the understanding of the effect of the water content, vacancies and initial sodium content on the reaction potential, capacity, conductivity and cyclability. In particular, operando Mössbauer will allow to track the iron redox activity and hence help separating the contribution of the second transition metal (M) from that of iron in the total electrochemical response.

The student will be based at CIC energiGUNE in Vitoria most of the time, but 3-6 months periods of research stay at Institut Charles Gerhardt Montpeiller, which is specialized, among others characterization techniques, in the study of electrode active materials with Mössbauer Spectroscopy.

Supervisor(s) contact: GALCERAN MESTRES Montserrat, mgalceran@cicenergigune.com
SAUREL Damien, dsaurel@cicenergigune.com