Ta-Ta2O5-电解液体系界面导电特性的分析与研究

Analysis and Research on the Dielectric Properties of Ta-Ta_2O_5-Electrolyte System

分析了钽电解电容器阳极氧化膜的形成过程,测试了阳极氧化膜工作的伏安特性。实验表明,阳极氧化膜在电场作用下具有整流效应,O2-跃过氧化膜/电解液界面位垒,在氧化膜中形成定向迁移,同时引发介质膜内二次电子的场助发射是该体系的主要导电机理。电解液中添加适量有机物可使电解液的闪火电压提高40 V以上,这有助于提高液体钽电解电容器的性能,扩大其应用范围。

Formation process of anodic oxide film of wet tantalum electrolytic capacitors is analyzed, and the I- U character of oxide film is tested. The results show that the tantalum anodic film has valve effect under the out electric field, and the main conductive mechanism of Ta-Ta2O5-electrolyte system is the single direction moving of O2^- through the interface energy barrier between the oxide filme and electrolyte, and leading to the emitting of second electronic as well. The sparking voltage of electrolyte will be increased by about 40 V as adding some organic matter into it, which will be help to improve the performance of wet tantalum electrolytic capacitors, and enlarge its application range.