Solid Electrolyte Interphase (SEI) Electrodes. Part 1. The Kinetics of Lithium in LiAlCl4-SOCl2

The lithium electrode is always covered by a film of lithium chloride which acts as solid electrolyte interphase (SEI). Macropolarization curves indicate that the Tafel slope is greater than 3 V for electrodes having SEI thicker than 400 Å. This confirms that the rds for the deposition-dissolution process is the migration of lithium cations through the SEI. Increasing the electrolyte concentration increases the interfacial capacitance and decreases the resistivity of the SEI. This is explained in terms of the effect of LiAlCl₄ concentration on the concentration of the lattice defects. The effect of the concentration of the electrolyte on the resistivity of the SEI decreases as the thickness of the SEI is increased. The growth rate of the SEI increases as the concentration of the electrolyte is increased.