Assessing Mesoscale Heterogeneities in Hard Carbon Electrodes through FIB-SEM Characterization, Manufacturing and Electrochemical Modeling

Abstract

Given the recent inclusion of sodium-ion batteries (SIBs) in the energy market, the optimization of their performance becomes a relevant research topic. At the electrode-level, the parameters selected during its manufacturing process influence its microstructure and, consequently, its electrochemical performance. Here, we address different manufacturing conditions of hard carbon (HC) negative electrodes by varying the solid content (35 wt% and 40 wt%) and the calendering degree (uncalendered and 30% calendered). The three-dimensional microstructure of each sample is acquired using focused ion beam (FIB) and scanning electron microscopy (SEM) technique, from which the real-shape of HC particles is extracted and used to generate input microstructures for a discrete element method (DEM) calendering model designed to address the mechanical electrode behavior and its effects on current collector deformation. Also, the 3D electrode microstructures are used in a finite element method (FEM) model to obtain the electrochemical performance for C-rates ranging from C/50 to C/5 and to compare these results with experimental ones. Furthermore, the DEM predictions are injected into the FEM model to validate them against the FIB-SEM reference. Overall, we study how manufacturing parameters influence the performance of HC electrodes, providing an important guideline for optimizing their production for SIBs applications.

Affiliated Institutions

• Centre National de la Recherche Scientifique FR
• Laboratoire de Réactivité et Chimie des Solides FR
• Roma Tre University IT
• IFP Énergies nouvelles FR
• Université de Picardie Jules Verne FR
• Laboratoire Amiénois de Mathématique Fondamentale et Appliquée FR

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