In-situ observation of morphological change in lead dioxide surface by EC-AFM

摘要

An Electrochemical Atomic Force Microscope (EC-AFM) was used to study the reaction of a lead dioxide electrode in sulfuric acid solution, when the reaction corresponding to what occurs at the positive electrode of a lead-acid battery took place. We observed continuous in-situ morphological change of the lead dioxide electrode and the potentiostatic transient, when the oxidation and reduction potentials were applied to the electrode. As a result, it was confirmed that lead sulfate crystals began to deposit from the moment when the reduction potential was applied and the reduction transient showed a sharp peak shape at the same time. On the other hand, the dissolution of lead sulfate crystals delayed from when the oxidation potential was applied. It took about 2 minutes for all crystals to dissolve, and the oxidation transient was recorded as a broad shape curve.