The Effects of NaHCO₃on the Voltage Delay of Mg Cell with AZ31B Magnesium Alloy in Mg(ClO₄)₂Electrolytic Solution

Abstract

The delayed action effect is a main obstacle for Mg/MnO 2 battery to deliver instantaneous power on discharge from an open-circuit condition. A new low-cost inorganic electrolyte consisting of 2 M Mg(ClO 4 ) 2 and 0.04 M NaHCO 3 was proposed and reduced the delayed parameters of the anode to a negligible degree even after aging of 16 d. The results from electrochemical impedance spectroscopy indicated that the addition of 0.04 M NaHCO 3 significantly enhanced the corrosion resistance of AZ31B magnesium alloy. Anodic utilization efficiency of AZ31B was also increased by 10% compared with the commonly-used Mg(ClO 4 ) 2 at a small current density of 2.5 mA cm −2 . The analysis of FT-IR and XPS results revealed that the composition of the corrosion product film formed in this new electrolyte was a mixture of MgO, Mg(OH) 2 , Mg 5 (CO 3 ) 4 (OH) 2 • 4H 2 O and Mg(ClO 4 ) 2 .

Effects of Macrosegregation and Microstructure on the Corrosion Resistance and Hardness of a Directionally Solidified Zn-5.0wt.%Mg Alloy

“…The values attributed for each one of the EC elements and chi-squared values (χ 2 ) are shown in Table 2. The use of this type of EC for different alloys can be found in the literature 7,[29][30][31] . The EC adopted in this manuscript was presented and used in a recent work with Zn-Mg alloys 7 .…”

Study of Polarization Characteristics of Corrosion Films on Magnesium in Sulfate-Containing Electrolytes

“…The Nyquist plots for the magnesium electrode in the investigated solutions are shown in Figures 8 and 9. The presence of two semicircles in the hodographs of electrochemical impedance most often refers to RC circuits describing the double electric layer and dense part of the film [5,30,31]. The electrochemical impedance technique was also used to addition analysis of charge transfer through corrosion films.…”

“…The proposed versions of electrical equivalents of electrochemical processes for magnesium electrodes contain a serial connection of RC-circuits, where the capacity is represented by an element with distributed parameters of Constant Phase Element (CPE) for describing a complex nature of charge transfer through a film and double layer [30]. When considering the case of partial coating of the surface with a dense corrosion film, their parallel connection is used [5,31].…”