Effect of Conditions of Ultrasonic and Electrochemical Etching on Morphology and Capacitance of Etched Aluminum Electrodes

Abstract

Aluminum foil is ultrasonically and electrochemically etched in a mixed aqueous solution of hydrochloric and sulfuric acid while varying etching time and ultrasound frequency. Next, aluminum oxide is formed by anodizing in a boric acid solution. Higher capacitance (92.4 μF cm−2) is obtained at the best etching time of 240 s and better ultrasound frequency of 120 kHz. Furthermore, higher ultrasound frequency leads to higher specifi c capacitance and longer etching time also leads to higher specific capacitance except an etching time of 300 s.