Abstract The reversal of the positive and negative electrodes in the magnesium-aluminum-sodium hydroxide primary battery is caused by the magnesium hydroxide film formed on the surface of magnesium in an alkaline solution. Combining the theory of crystal defects, it is known that some ions will penetrate into the interior of the magnesium hydroxide crystal and cause it to fall off. Therefore, the reversed magnesium electrode was immersed in an electrolyte solution and the original cell was re-formed. The process of the “ion penetration effect” damaging the protective film on the metal surface can be visually perceived by the reappearance of the positive and negative electrodes on the electrode. This research can provide a reasonable explanation for the abnormal reaction rates of some metals and metal oxides in different acid or salt solutions.
LIN Qian-Nan. Destructive Effect of Chloride Ion Penetration on Metal Protective Film[J]. Chinese Journal of Chemical Education, 2025, 46(15): 113-117.
