Implications of Local Current Density Variations on Lithium Plating Affected by Cathode Particle Size

Alexander Abboud, Eric Dufek, Boryann Liaw

March 2019 - A three-dimensional electrochemical model of a rechargeable lithium metal battery is constructed with a lithium metal anode and a LiNi0.6Mn0.2Co0.2O2 (NMC-622) cathode. The model is created with a randomly packed distribution of active cathode material particles packed in sizes of 1.5, 3.0 and 4.5 ┬Ám, respectively in each simulation case. The current density field from the cathode to the anode through the separator is examined. Higher variability occurs on the cathode side as the electric current field is distorted by the difference in the electrical properties between the electrolyte and the active material particles. The variance in the current decreases moving to- wards the anode side, but does not reach uniformity. The smallest particle size of the cathode particles shows the lowest variance in the current density distribution on both the cathode and anode side of the separator. The results suggest that smaller particle size could lead to more uniform lithium deposition during cycling in cells with lithium metal anodes.

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