Effects of current density on anodizing behavior, micro-structure, and electrical properties of ZrO2-coated Al foils

Abstract

The effect of current density on the anodizing behaviors, micro-structure, and electric properties of ZrO2-coated Al samples is reported. The experiment is performed by coating ZrO2 on the surface of etched Al foils and anodizing in 2-methyl-1,3-propanediol (MPD)-boric acid electrolyte at current densities of 0.01, 0.05, and 0.10 A/cm2 at 700 V. The samples are characterized using X-ray diffraction, field emission transmission electron microscopy, and electrochemical impedance spectroscopy. Marked enhancements in anodization rate, and specific capacitance are achieved by the increase in current density during anodization. A maximum enhancement of 14.8% in specific capacitance and increase of 25.7% in charging ability are realized by anodizing at 0.10 A/cm2. The specific capacitance is finally increased by 54.3% after ZrO2 coating and current density modification. This work provides a valuable forerunner for research into the effect of current density on the anodizing behavior, micro-structure, and electric properties of valve metal oxide-coated Al foils.