| 摘要 |
PURPOSE:To obtain a positive electrode plate maintaining a good charging feature even if left overdischarged by chemically converting a chemically-unconverted positive electrode plate in sulfuric acid solved with sodium perchlorate. CONSTITUTION:Chemical conversion is performed according to a normal method in sulfuric acid solved with sodium perchlorate at a rate of 1g/1l. Sodium perchlorate as a corrosion agent is added to a chemical conversion liquid to chemically convert a positive electrode plate, thereby a corrosion layer with a sufficient thickness is formed on the interface between a lattice and the active material in advance, thus even if a battery is left overcharged, sulfuric acid is hard to diffuse due to the thickness of the corrosion layer, and the lead-reaction of sulfuric acid is suppressed. Accordingly, the charging feature after being left overdischarged can be prevented from being deteriorated. |
