In situ observation of morphology change in lead dioxide surface for lead-acid battery

An electrochemical atomic force microscope (EC-AFM) was used to study the r eaction of a lead dioxide electrode in sulfuric acid solution, while the re action corresponding to what occurs at the positive electrode of a lead-aci d battery took place. We observed continuous in situ morphology change of t he lead dioxide electrode and the potentiostatic transient, when the oxidat ion 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 was delayed from the moment when the oxidation poten tial was applied. It took about 2 min for all the crystals to dissolve, and the oxidation transient was recorded as a broad shaped curve. (C) 2001 Pub lished by Elsevier Science B.V.