Effect of trimethyl phosphate additives on etched tunnel formation of aluminum foils
Anode aluminum foils used in the aluminum electrolytic capacitors are typically produced through the electrochemical tunnel etching process,which aims to create a high density of etched tunnels in order to increase the specific surface area and specific capacitance.However,the presence of the merged tunnels and uneven distribution of tunnels severely hinder the improvement of the specific capacitance for the etched aluminum foil.To address this issue,the nucleation sites of tunnels were controlled by adding trimethyl phosphate(TMP)as an additive into the etchant.The addition of an appropriate concentration of TMP has dual effects.Firstly,it reduces the surface tension of the etchant and improves the wettability between the aluminum foil and etchant.Secondly,this improved wettability directly decreases the dissolution resistance of the aluminum foil surface,leading to a significant reduction in the nucleation resistance of etched tunnels.As a result,the specific surface area of the etched aluminum foil is substantially increased.The morphology characterization and statistical analysis results confirm that the addition of 1％(mass fraction)TMP in the etchant greatly improves the uniformity of tunnel distribution during the electrochemical etching process.Moreover,the specific surface area of the etched aluminum foil is enhanced by approximately 50％compared to the blank sample.This research provides novel insights for the production of high-performance anode aluminum foils and demonstrates the efficacy of using TMP as an additive to regulate the formation of the etched tunnels.
国家科技期刊平台
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