Study Of The Electrolytic Etching Of Ce Aluminum Foil For High Voltage Anode Of Electrolytic Capacitor

The high performance, miniaturization, namely high specific capacitance of the aluminum electrolytic capacitor is the current development tendency. Enhance the electrolytic capacitor aluminum foil's specific capacitance by means of the rare earth micro alloying, which can make full use of favorable resources and enhance the competitive power of the related products. The specific capacitance of the electrolytic capacitor is related to the magnification of the extending surface area of the aluminum foil.So it's necessary to study the effect of rare-earth Ce on the electrolytic etching of electrolytic capacitor aluminum foil.This research take Ce aluminum foil of different Ce content and high pure aluminum foil as main subject investigated. Through cold rolling of semi-manufactured aluminum foil and recrystallization annealing of aluminum foil, which be made into 0.11mm thick. And through fore treatmenting of aluminum foils which have been gived appropriate size, electrolytic polishing, DC electrolytic etching, post treatment and testing of the etching specific capacitance. In the experiment, study the etching pattern of the etched aluminum foil by means of the Axiovert25 metallographic microscope and the QUANTA400 environmental scanning electronic microscope. And using the SI1287+SI1260 impedance instrument to test AC electrochemical impedance spectroscopy (EIS) and study the specific capacitance of the etched aluminum foil. At last, through studing the experiment findings, to find out the effect of rare-earth Ce on the DC electrolytic etching of aluminum foil.The results showed that the voltage or current gived, the component and temperature of electrolytic solution and the etching time are the main external factors on electrolytic etching.But in this experiment, along with the Ce content increases, the aperture of the corrosion pit of the etched aluminum foil becomes smaller, but the number of it increases and the depth becomes bigger. And the results also showed, compare to high pure aluminum foil, the specific capacitance of the rare-earth aluminum foil alloyed with Ce in proper content is higher. Besides, the external etching condition of the rare-earth aluminum foil in diffent Ce content can attain the biggest etched specific capacitance is diffent. The etched specific capacitance in rare-earth aluminum foil with Ce in a concentration of 0.0074% can reach 29.72μF/cm2 which is the biggest.