长寿命铝电解电容器用化成箔制备工艺研究

Preparation process of chemical foil for long-life aluminum electrolytic capacitors

通过阳极氧化法将高压腐蚀箔在磷酸水溶液中低温氧化形成前置氧化多孔膜,在前置氧化膜的基础上采用低温、低浓度的硼酸或氢氧化钠溶液进行小电流化成,可制备长寿命铝电解电容器用化成箔。X射线衍射(XRD)和扫描电子显微镜(SEM)测试结果表明:高压腐蚀箔在前置氧化膜基础上形成的化成箔表面氧化膜为较疏松的无定型氧化膜。经过电容器老练对比试验表明,化成箔中无定型氧化膜更容易被电容器中电解液修复,并且在老练和耐久性试验时的高温作用下,疏松的无定型氧化膜可以部分转化为致密的晶型氧化膜(γ^(1)-Al_(2)O_(3)),使电容器容量得到提升,损耗和漏电流长时间保持稳定,电容器的性能得到较大改善。

The high-voltage etched foil was oxidized in aqueous phosphoric acid solution at low temperature and a pre-oxidized porous membrane was formed by anodic oxidation.On the basis of this pre-oxidized membrane,low-current chemistry was performed using a low-temperature,low-concentration boric acid or sodium hydroxide solution to prepare the chemistry foil for long-life aluminum electrolytic capacitors.X-ray diffraction(XRD)and scanning electron microscopy(SEM)test results showed that the oxide film formed on the surface of the chemical foil was a loose and amorphous oxide film.The comparison test of the capacitor aging showed that the amorphous oxide film in the chemical foil was easier to be repaired by the electrolyte in the capacitor,and the loose amorphous oxide film could be partially transformed into dense crystalline oxide film(γ^(1)-Al_(2)O_(3))under the effect of high temperature in the aging and durability test.As a result,the capacitor capacity was improved and the loss and leakage current was well maintained for a long time,and the performance of the capacitor was greatly enhanced.