In situ synthesis of high-performance electrodes for Li-ion batteries
We wish to establish, very systematically, close relationships between stoichiometry, morphology, structure and electrochemical properties of fully characterized positive electrode powders for Li-Ion batteries. An exhaustive approach (precursors, thermal treatments under various pO2, substitution (with Fe, Mg, ….)) will be used to tune the synthesis of high-performance Li(Ni,Mn)2O4-δ spinels.
Phase equilibria during synthesis will be explored in situ using T-controlled X-Ray or Neutron diffraction under various atmospheres and with different sintering additives, using the D20 diffractometer @ ILL for instance. Neutron diffraction is essential to characterize cation stoichiometry and ordering (Ni and Mn) and oxygen vacancies.
Structural characterizations of powders and/or materials prepared at large scale at UMICORE will be performed, using high-resolution neutron diffraction @ ILL with the D2B diffractometer. D1B would also be used for temperature-controlled studies.
Electrochemical studies will be performed on laboratory and industry-like cells (“18650” cylindrical format) to understand what governs the voltage-composition profiles, the reversibility, the contributions of Ni or Mn. Operando investigations during battery cycling will be conducted with neutron diffraction, synchrotron XRD, X-Ray Absorption, at various T, thanks to several cells already developed, jointly.