Formation of oxide films for high‐capacitance aluminum electrolytic capacitor by liquid‐phase deposition and anodizing

Abstract

Liquid‐phase deposition (LPD) treatment and anodizing were used to form oxide layer for a high‐capacitance aluminum electrolytic capacitor. Formation of protective oxide layers and modification of LPD conditions make it possible to prolong the LPD duration and lead to the formation of TiO2 and NaF deposits on aluminum. A titanium oxide/aluminum oxide mixed layer was formed by a combination process of LPD treatment and anodizing. The capacitance of the formed layer was about 300% higher than that of an anodic oxide film formed on electropolished aluminum. The structures and compositions of the films that were formed were determined by transmission electron microscopy, scanning electron microscopy, and Rutherford backscattering spectroscopy. Copyright © 2015 John Wiley & Sons, Ltd.