Lift-Out Specimen\nPreparation and Multiscale Correlative\nInvestigation of Li-Ion Battery Electrodes Using Focused Ion Beam-Secondary\nIon Mass Spectrometry Platforms

Advanced characterization is paramount to understanding\nbattery\ncycling and degradation in greater detail. Herein, we present a novel\nmethodology of battery electrode analysis, employing focused ion beam\n(FIB) secondary-ion mass spectrometry platforms coupled with a specific\nlift-out specimen preparation, allowing us to optimize analysis and\nprevent air contamination. Correlative microscopy, combining electron\nmicroscopy and chemical imaging of a liquid electrolyte Li-ion battery\nelectrode, is performed over the entire electrode thickness down to\nsubparticle domains. We observed a distinctive remnant lithiation\namong interparticles of the anode at the discharge state. Furthermore,\nchemical mapping reveals the nanometric architecture of advanced composite\nactive materials with a lateral resolution of 16 nm and the presence\nof a solid electrolyte interface on the particle boundaries. We highlight\nthe methodological advantages of studying interfaces and the ability\nto conduct high-performance chemical and morphological correlative\nanalyses of battery materials and comment on their potential use in\nother fields.