Rechargeable Li/Na-ion batteries studied by in-situ Mössbauer techniques

Improving lithium and sodium ion batteries requires the study and the development of new promising electrode materials with high energy densities. Electrode materials are the most important components in the operation and the performances of Li- and Na-ion batteries. Therefore, the understanding of the electrochemical processes in the cells needs a detailed investigation of their reaction mechanism by combining various characterization techniques.
Mössbauer spectroscopy has been applied to a variety of fields including chemistry, physics, geology, biology…. In the domain of electrochemical energy storage, Mössbauer spectroscopy has been used as a powerful tool to investigate the local electronic and structural properties of electrode materials and to determine their reaction mechanisms during charge and discharge of Li- and Na-ion batteries. Indeed, Mössbauer spectroscopy is an efficient technique for the characterization of the the local electronic structure around the probed element in crystalline, glass or amorphous materials. It allows one to study oxidation states, local coordination and bonding. In this work, the study of the reaction mechanism of some new electrode materials for lithium and sodium-ion batteries using complementary information from operando X-ray diffraction (XRD), Mössbauer spectroscopy and synchrotron Mössbauer source (SMS) will be presented.