Publications by authors named "A Demortiere"

A novel approach for investigating the formation of solid electrolyte interphase (SEI) in Na-ion batteries (NIB) through the coupling of in situ liquid electrochemical transmission electron microscopy (ec-TEM) and gas-chromatography mass-spectrometry (GC/MS) is proposed. To optimize this coupling, experiments are conducted on the sodiation of hard carbon materials (HC) using two setups: in situ ec-TEM holder and ex situ setup. Electrolyte (NP30) is intentionally degraded using cyclic voltammetry (CV), and the recovered liquid product is analyzed using GC/MS.

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The technique known as 4D-STEM has recently emerged as a powerful tool for the local characterization of crystalline structures in materials, such as cathode materials for Li-ion batteries or perovskite materials for photovoltaics. However, the use of new detectors optimized for electron diffraction patterns and other advanced techniques requires constant adaptation of methodologies to address the challenges associated with crystalline materials. In this study, we present a novel image-processing method to improve pattern matching in the determination of crystalline orientations and phases.

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Li-O batteries (LOB) performance degradation ultimately occurs through the accumulation of discharge products and irreversible clogging of the porous electrode during the cycling. Electrode binder degradation in the presence of reduced oxygen species can result in additional coating of the conductive surface, exacerbating capacity fading. Herein, a facile method to fabricate free-standing is established, binder-free electrodes for LOBs in which multi-wall carbon nanotubes form cross-linked networks exhibiting high porosity, conductivity, and flexibility.

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LiAlGe(PO) (LAGP) is a promising oxide solid electrolyte for all-solid-state batteries due to its excellent air stability, acceptable electrochemical stability window, and cost-effective precursor materials. However, further improvement in the ionic conductivity performance of oxide solid-state electrolytes is hindered by the presence of grain boundaries and their associated morphologies and composition. These key factors thus represent a major obstacle to the improved design of modern oxide based solid-state electrolytes.

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Micro-batteries are attractive miniaturized energy devices for new Internet of Things applications, but the lack of understanding of their degradation process during cycling hinders improving their performance. Here focused ion beam (FIB)-lamella from LiMn Ni O (LMNO) thin-film cathode is in situ cycled in a liquid electrolyte inside an electrochemical transmission electron microscope (TEM) holder to analyze structural and morphology changes upon (de)lithiation processes. A high-quality electrical connection between the platinum (Pt) current collector of FIB-lamella and the microchip's Pt working electrode is established, as confirmed by local two-probe conductivity measurements.

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