Brunetti, G.Robert, D.Bayle-Guillemaud, P.Rouvière, J.L.Rauch, E.F.Martin, J.F.Colin, J.F.Bertin, F.Cayron, C.2014-11-142014-11-142014-11-14201110.1021/cm201783zhttps://infoscience.epfl.ch/handle/20.500.14299/108835A recent transmission electron microscopy (TEM) method using precession electron diffraction (PED) was used to obtain LiFePO4 and FePO 4 phase mapping at the nanometer-scale level on a large number of particles of sizes between 50 and 300 nm in a partially charged cathode. Despite the similarity of the two phases (the difference of lattice parameters is <5%), the method gives clear results that have been confirmed using high-resolution transmission electron microscopy (HRTEM) and energy-filtered transmission electron microscopy/electron energy loss spectroscopy (EFTEM/EELS) experiments. The PED maps show that the particles are either fully lithiated or fully delithiated and, therefore, bring a strong support to the domino-cascade model at the nanoscale level (scale of a particle). A core-shell model or spinodal decomposition at mesoscale (scale of agglomerates of particles) is possible. Size effects on the transformation are also discussed. © 2011 American Chemical Society.AgglomerationCore-shell modelelectron diffractionElectron energy loss spectroscopyElectronsEnergy dissipationEnergy filtered transmission electron microscopyEnergy-loss spectroscopyHigh resolution electron microscopyHigh resolution transmission electron microscopyLiFePOLiFePO4LithiumLithium alloyslithium batteriesMesoscaleNano-meter-scaleNanoscale levelsphase mappingPhase mappingsprecession electron diffractionSize effectsSpinodal decompositionStream flowTEMTransmission electron microscopytext::journal::journal article::research article