Effects of the mixing sequence on the graphite dispersion and resistance of lithium-ion battery anodes

The performance of lithium-ion battery electrodes is influenced by particle dispersion in the slurry used for their production. In this study, we elucidate the effects and mechanism of the binder mixing sequence on the characteristics of the slurry used in the production of negative electrodes. Therefore, we optimize the preparation of the negative electrode slurry by evaluating the electrode characteristics resulting from changing the binder mixing sequence. During the preparation of the electrode slurry, the state of the adsorption of the binder to the particle changes when the sequence of binder addition is changed. The change in the adsorption state of the binder influences the particle dispersion in the slurry, rheological properties of the slurry, and packing characteristics of the particles. Under the influence of the aforementioned changes, electrodes possessing identical compositions exhibited different performances. The slurry in which the particles were dispersed produced an electrode possessing a low volume-resistivity, whereas the slurry in which the particles were agglomerated produced an electrode with a high volume-resistivity. Evidently, controlling the adsorption state of the binder by altering the binder mixing sequence is essential for fabricating electrodes possessing a low volume-resistivity.