Influence of Ethylene Glycol on the Electropolishing of Titanium and the Electrochemical characteristics in PEMFC Environments

• Published in: Corrosion science and technology Vol. 24; no. 4; pp. 212 - 229
• Main Authors: Hyun-kyu Hwang, Seong-jong Kim
• Format: Journal Article
• Language: Korean
• Published: 한국부식방식학회 31.08.2025
• Subjects: Anti-corrosion; Eco-friendly electrolyte; Electropolishing; PEMFC; Titanium; Titanium; Eco-friendly electrolyte; Anti-corrosion; PEMFC; Electropolishing
• ISSN: 1598-6462; 2288-6524
• DOI: 10.14773/cst.2025.24.4.212

This research investigated the effects of electropolishing on titanium using choline chloride-based deep eutectic solvents with varying ethylene glycol molar ratios (1:1, 1:2, 1:3) and applied potentials, as well as the electrochemical characteristics in a PEMFC simulated environment. The analysis of the potentiodynamic polarization curves revealed that a choline chloride to ethylene glycol ratio of 1:3 resulted in the most stable current density and the broadest potential range. This stability was attributed to an increased concentration of active ions participating in the electrochemical reaction, which led to the formation of a significant amount of oxygen-bonded metal-organic complexes, thereby stabilizing the dissolution reaction. In titanium (Ti) electropolished under optimal conditions, additional TiO₂ crystalline phases were observed. The investigation of the electrochemical characteristics in the PEMFC simulation solution presented that mechanically polished titanium did not meet U.S. Department of Energy standards, whereas the specimens electropolished under optimal conditions did. This improvement is due to the beneficial influence of the TiO₂ formed during the electropolishing process on the electrochemical characteristics.