123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Scholars in Electrochemistry
Room No. Room 407+408
Time THU 10:10-10:20
Code ELEC.O-8
Subject A Quantitative Method to Measure Corrosion Current on Zinc Metal Electrodes
Authors Kiyoung Kwon, Hyun Deog Yoo*
Department of Chemistry and Chemical Institute for Functional Materials, Pusan National University, Busan 46241, Korea
Abstract Researches on zinc metal-based batteries have attracted considerable attention as a candidate for post lithium-ion batteries. Zinc is one of few metal anodes that are compatible in aqueous as well as non-aqueous electrolytes, providing a large theoretical capacity of 820 mAh g−1. However, in aqueous electrolytes, zinc metal anode suffers from hydrogen evolution reaction (HER), by which zinc is irreversibly consumed or corroded continually. Exact estimation of the corrosion current has been a challenge in the development of Zn-based batteries. Measurement of corrosion current by conventional Tafel analysis meets serious problems because the cathodic current reflects deposition of Zn metal as well as HER, inhibiting exact measurement of corrosion current. Herein, we developed "Depo-Rest-Diss" method to quantify the corrosion current without such interference from the deposition of Zn. The “Depo-Rest-Diss” method was successfully applied to the quantification of corrosion current in aqueous electrolytes with various pH and concentration. The “Depo-Rest-Diss” method and electrochemical impedance spectroscopy confirmed that saturated ZnSO4 (ca. 3.2 M) + 0.075 M Li2SO4 delivers the lowest corrosion current compared to the other electrolytes probably because the activity of water in such concentrated electrolyte is low enough to suppress the kinetics of HER. Thus developed "Depo-Rest-Diss" method can be generally applied to determine the corrosion current on various metal electrodes.
E-mail kiyoung.kwon@pusan.ac.kr