Designing Graphite-Based Positive Electrodes and Their Properties in Dual-Ion Batteries Using Particle Size-Adjusted Active Materials

In almost all state-of-the-art lithium-ion batteries, the negative electrode is made from graphite. For dual-ion batteries (DIBs), graphite electrodes can even be used as negative and positive electrodes as the electrolyte provides both cations and anions for energy storage. As the amount of active material is very high in graphite electrodes, one of the main structure-controlling parameters is its particle size distribution (PSD). Based on changes in the active material particle size and resulting changes in electrode structure, the corresponding cell characteristics like coulombic efficiency or power density are strongly affected. Herein, results for graphite positive electrodes manufactured with different PSDs of one typical commercial synthetic graphite are displayed. A high-performance single-wheel air classifier is used to create the differently distributed graphite particle fractions that do not vary in particle shapes for all fractions created. To gain a better understanding of the particle size impact on electrode properties, the electronic and mechanical properties, as well as the electrode structure, are investigated. The electrochemical performance of the Li metal/graphite system is correlated with structure properties influenced by PSD.