Electrolytic Separation of Iodine from LiCl–KCl–LiBr–LiI Melt and Recovery of Iodine Gas with Copper

• Published in: ECS transactions 2022-09, Vol.109 (14), p.165-173
• Main Authors: Norikawa, Yutaro, Iizuka, Masatoshi, Nohira, Toshiyuki
• Format: Article
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/10914.0165ecst

The separation and recovery of iodine from LiCl–KCl–LiBr–LiI melt was investigated at 723 K. Cyclic voltammograms at a glass-like carbon electrode showed that I 2 gas generates at more negative potential compared with Cl 2 and Br 2 gases. Potentiostatic electrolysis for I 2 gas generation was conducted at glassy carbon and Au electrodes, where the generated I 2 gas was collected by a Cu mesh placed at the top of the cell. XRD confirmed that the Cu mesh changed to CuI. At a glass-like carbon electrode, recovery efficiencies of iodine were 64% and 97% at 3.2 V and 3.3 V vs. Li + /Li, respectively. The recovery efficiency at an Au electrode was 93%. However, a part of the Au electrode dissolved into the melt. Finally, a continuous recovery method was proposed, in which the generated I 2 gas was recovered by several independently recoverable Cu meshes packed in a borosilicate gas outlet tube.