Formation and mechanistic analysis of self-etched tunnels on the surface of aluminum foil by the electrodeposition of trace Cu to form an electrolytic capacitor

Autor: Kaifang Zhu, Fei Liu, Jinke Cheng
Rok vydání: 2020
Předmět:
Zdroj: Journal of Materials Science: Materials in Electronics. 31:6937-6947
ISSN: 1573-482X
0957-4522
DOI: 10.1007/s10854-020-03257-2
Popis: To get rid of the dependence on an external current during the electrochemical etching of aluminum foil, we explored a self-etching tunnel method. Specimens were prepared by electrodepositing trace amounts of Cu onto the surface of aluminum foil, and self-etching occurred in the electrolyte without current input. The effect of electrodeposited Cu on the self-etching of tunnels on the aluminum foil was examined, and the mechanism was investigated by the open circuit potential, SEM, polarization curve, EIS, weight loss, thickness reduction, pit density, and tunnel size. The results of the analysis showed that Al–Cu microbatteries with Al as the anode and Cu as the cathode were formed by the uniform electrodeposition of trace Cu on the aluminum foil surface. The current of Al–Cu microbatteries enhanced the etching drive of aluminum foil, resulting in an accelerated tunnel self-etching. When the electrodeposition time was 10 s, samples showed better etching performance, and the pitting density and weight loss were 49.76% and 21.29%, respectively. The logarithmic free corrosion current density log(icorr) of the aluminum foil increased from − 1.532 A cm−2 to − 1.432 A cm−2, the free corrosion potential Ecorr decreased from − 0.711 V to − 0.807 V, and the reaction resistance R decreased from 14.15 Ω cm−2 to 8.399 Ω cm−2. The tunnels were self-etched spontaneously without an applied current and were easy to generate.
Databáze: OpenAIRE
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