Séminaire, Dr. Claire Villevieille (Paul Scherrer Institut)

Abstract :

Since the introduction of lithium-ion batteries, layered LiCoO2 and graphite have been the most widely used positive and negative electrode materials, respectively. But the modern nomad electronic devices and future electric vehicles need novel lithium-ion batteries with higher energy density and power. An overview of new potential candidates for positive and negative electrode for the next generation of lithium and sodium batteries will be given. In the first part of the talk, it will be described how to increase the specific charge of the electrodes beyond the benchmark of 372 mAh/g (graphite) and 150 mAh/g (LiCoO2), respectively, by modifying the synthetic strategy as well as “playing” with the surface and interfaces. The second part will focus on the analysis of the electrochemical reactions occurring during cycling of selected materials by combination of different operando characterization techniques such as synchrotron X-Ray diffraction, neutron diffraction, Raman spectroscopy, etc. The third part will be dedicated to sodium batteries/Li-S batteries and performances of conversion reaction materials used as negative electrode. The role of the electrode engineering as well as surface degradation will be discussed.