Chronopotentiometric Analysis of the Anode Dissolution Process in Dimethyl Sulfone–Aluminum Chloride Electrolytic Solution

Toward the commercialization of aluminum electrodeposition, unveiling the anode dissolution process in a sustainable electrolyte is essential. Herein, to gain more insight into the anode dissolution process in dimethyl sulfone (DMSO 2 )–aluminum chloride (AlCl 3 ) electrolyte solution, we performed chronopotentiometry measurements using Pt disk electrodes. In this system, the anode dissolution reaction exhibits two-wave behavior with a positive potential shift of +1.0 V. The Coulombic efficiency, reaction potential, and multiple reverse chronopotentiometry measurements show that the second-stage anode dissolution reaction is a three-electron-transfer process from Al 0 and AlCl 4 − to Al 2 Cl 7 − . The transition of the anode dissolution reaction from the first to the second-stage occurs because Al (DMSO 2 ) 3 3+ is not stably formed owing to DMSO 2 depletion near the electrode during the anode dissolution reaction.