The diffusion dynamic of Ti in liquid cathodes during molten oxide electrolysis

Molten oxide electrolysis (MOE) equipped with a liquid cathode is a prospective and sustainable process to reduce carbon footprint of metallurgical industry. However, the ultrahigh operating temperature significantly impedes the in-depth investigation of the cathodic process, which further limits the large-scale application of MOE. Here, we conduct a series of equivalent diffusion experiments of Ti in liquid Cu and Sn at operating temperature of up to 1673 K. The time-dependent snapshots of Ti atom distribution visually and quantitatively demonstrated the diffusion behaviour of Ti in those liquid cathodes for the first time. In addition, the diffusion coefficient and limiting current density of Ti in liquid Cu and Sn are obtained by integrating the experimental results, thermodynamic calculations, and computer simulations. Based on those new findings, the potential application of Cu and Sn cathodes in MOE was re-evaluated. Collectively, this study presents valuable insights for the industrial application of MOE.