Electrodeposition, Anodic Oxidation - The Preparation Of Aluminum Electrolytic Capacitor Anode Materials,

Adopting high-purity aluminium foil as the cathode of the anodic oxidation.The influence of the current density, the oxidized time, concentration of electrolyte and temperature on electrochemical performance of anodic oxidation film was studied.Through analyzing the surface micro structure morphology of aluminum anodic films,combining with the results of polarization curves of oxide film on aluminum, which was tested in 1mol/L NaCl solution, this paper discussed the micro-mechanism of different corrosion resistance of aluminum under the condition of various parameters. The results show that good uniformity and high corrosion resistance anodic oxidation film was got under the conditions: temperature of 25 to 30℃, the oxidized time for 60min, current density for 20mA/cm², acid concentration 200g/L. Meanwhile, test galvanostatic charge-discharge curves with current of 1mA,in 0.15mol/L (NH₄)₂SO₄ solution, and the results showed that material has good cycle characteristics, and the specific capacitance can reach 101μF/cm², and after cycling 500 times, 84.2% of the specific capacitance still remained, showed good cycle-life.Contrast studied on the deposition experiment of anodized aluminum in which the aluminum sheet as cathode both before and after. The experimental results showed that the aluminum of non-anodic oxidation, deposition layer cannot combine together well with aluminum sheet, due to be not had the catalytic activity, the large expansion coefficient of aluminum sheet which was different from some the others. The deposit layer shed from the surface of aluminum after heating. However, Aluminum foil after anodic oxidation and then deposition was carried, the deposit layer well combined with the aluminum sheet, still keep good adhesion after heating.At last, we analyzed the surface microstructure of morphology, and tested the galvanostatic charge-discharge curves after deposition, discussed the process parameters on the influence of material specific capacitance. Results showed that, the specific capacitance can reach 106μF/ cm², can increase 4% before deposition and without adding thiourea. And after adding 1g thiourea, the specific capacitance can reach 125μF/cm², increase 17.9% before add thiourea,and improve 23.8% before deposition. After cycling 500 times, the curve has still showed good charge-discharge characteristics, and specific capacitance remained of 87.2% before for circulation, showed good cycle-life and stable electrochemical performance.