Wetting characteristics of Li-ion battery electrodes: Impact of calendaring and current collector contact angle - A Lattice Boltzmann Method investigation

초록

Calendaring is a common process for enhancing the power density of Li-ion battery electrodes. In this study, the Shan-Chen-based Lattice Boltzmann Method is used to investigate the effects of different calendaring levels (0%, 10%, 20%, and 25%) on the wetting behavior of a Li-ion battery electrode. The actual contact angles between the electrolyte and battery components are incorporated, and the GPU-accelerated in-house code is developed to facilitate adequate meshing. An increased calendaring degree leads to a longer saturation time and increases gas entrapment within the cathode structure. The findings provide valuable insights into the dynamics of the electrolyte wetting process within the porous structure as calendaring levels change. The positioning of the pores and electrode particles strongly affects the electrolyte imbibition rate. In addition, this study examines the influence of the contact angle between the electrolyte and current collectors as a function of calendaring degrees. A 15 degrees contact angle results in marginally lower gas entrapment at 25% calendaring while consistently showing lower imbibition rates across all calendaring levels. At lower calendaring cases, 35 degrees and 60 degrees contact angle cases perform nearly the same, while at higher calendaring, the 60 degrees case outperforms the 35 degrees case but at the expense of higher gas entrapment.

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