有機抑制劑對金屬空氣電池之陽極材料的腐蝕影響研究

Effects of Organic Inhibitors on the Corrosion of Anode in Metal-air Battery

如何適度的抑制陽極金屬材料的自腐蝕速率，是金屬空氣電池研發的重要議題。本研究的前期結果已證實聚乙二醇（PEG）有機腐蝕抑制劑在極短時間內，可迅速影響鋅陽極在8M KOH電解質中的陰極反應並且大幅降低其腐蝕速率。目前的研究目標則是利用電化學交流阻抗的長期監測與動態極化曲線測試，探討上述兩種有機抑制劑對於鋅陽極的保護效率之經時變化情形。實驗結果顯示，PEG600的保護效率優於PEG400。然而，PEG有機抑制劑的保護效率在10天至30天之間會遽減約16%，其原因明顯地與有機抑制劑的薄膜阻抗衰退有關。此外，PEG有機抑制劑長期浸漬的保護效率劣化與電化學交流阻抗變化行為可適切地使用三種不同的模擬等效電路加以解釋。

How to properly suppress the self corrosion rate of metal anode is an important topic in the research of metal-air battery. Our previous study has verified that the polyethylene glycol(PEG) can quickly affect the cathodic behaviors of Zn anode in 8 M KOH electrolyte and dramatically decrease the corrosion current within extremely short time. The goal of this present research is to utilize the variation of protection efficiency of PEG with immersion time by the methods of long-term monitoring of the electrochemical impedance as well as the potentiodynamic polarization curves measurements. The results indicated that the protection efficiency of the PEG600 is superior to the PEG400. However, the protection efficiency of PEG organic corrosion inhibitors can make a reduction of about 16% hurriedly during the period from 10 days to 30days. This decline of protection efficiency of organic inhibitors is obviously related to the degradation in their impedances. Moreover, according to changes in impedance characteristics during the long term immersion, three different equivalent circuits were proposed to explain the degradation in protection efficiency of PEG organic inhibitors.