Investigation of the Redox Potential of Lithium and Its Dissolution in the LiCl–KCl Eutectic

Abstract

This present paper reports two fundamental thermodynamic data, including redox potential of Li+ and dissolution rate of metallic lithium in the LiCl–KCl eutectic for promoting the development of metallic lithium. Firstly, data from the first-principles molecular dynamics (FPMD) simulation was used for deep potential (DP) model training. The model’s reliability was then evaluated by the consistency of the energy, force, and radial distribution functions by comparing with FPMD simulation. After that, machine learning-driven molecular dynamics was performed by deep potential molecular dynamics (DPMD) to predict the redox potential of Li+/Li vs Cl2/Cl− in the LiCl–KCl eutectic. Compared with electromotive force measurements results, the maximum relative error is 6.86%. Finally, we investigated the effects of current density and temperature on lithium metal dissolution rate in the LiCl–KCl eutectic by the strategy of current reversal chronopotentiometry, respectively. In the current density range (0.041–0.245 A cm−2), the effect of current density on the dissolution rate of metallic lithium is negligible. As expected, lithium metal prefers to dissolve at high temperatures, and the activation energy of dissolution of lithium in LiCl–KCl eutectic is Ea = 27.78 kJ·mol−1.