Phase Transitions in Li2MnO3 Electrodes at Various States-of-Charge

Francis S. Amalraj (1) , Luba Burlaka (1) , Christian M. Julien (2) , Alain Mauger (3) , Daniela Kovacheva (4) , Michael Talianker (5) , Boris Markovsky (1) , Doron Aurbach (1)

1 Department of Chemistry, Bar-Ilan University
2 PECSA - Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques
3 IMPMC - Institut de minéralogie et de physique des milieux condensés
4 Institute of General and Inorganic Chemistry, Academy of Sciences
5 BGU - Ben-Gurion University of the Negev

We studied the structural transformations from the layered-type to spinel-type ordering upon galvanostatic charging (Li+ extraction) of Li2MnO3 electrodes. We have determined by X-ray, electron diffraction techniques and Raman spectroscopy analyses that these transformations partially occurred even at the initial states-of-charge, at potentials of 4.3 - 4.5 V, and in fully charged (4.7 V) and discharged (2.0 V) states as well. The above transformations are evident also from the analysis of the intrinsic magnetic properties of Li2MnO3 electrodes that indicate short-range spin correlations typical for the Li2Mn2O4 and LiMn2O4 spinel-type structures, depending on the state of charge and the C-rates used for the cycling.

Mots clés: Li2MnO3; electrochemical delithiation; structural transformations; spinel-type ordering; electron diffraction; magnetic characteristics

Domaines: Physique Quantique [quant-ph]

Francis S. Amalraj, Luba Burlaka, Christian M. Julien, Alain Mauger, Daniela Kovacheva, et al.. Phase Transitions in Li2MnO3 Electrodes at Various States-of-Charge. Electrochimica Acta, 2014, 123, pp.395-404. ⟨10.1016/j.electacta.2014.01.051⟩. ⟨hal-00983241⟩