|
The systematic study of this thesis, the the lead direct plating of the aluminum surface, the process is characterized by the aluminum surface plating lead process without going through secondary dip zinc pre-plated copper, pre-nickel plated, coated conductive layer complex pre-processing; simply some simple chemical and electrochemical processing, you can direct the aluminum matrix DC power placed in the added dispersant and stabilizer lead plating solution plating. Determined by single factor and orthogonal experiment direct plating process and best lead formulation, process: substrate polished the net → activation → pickling → → degreasing → alkali corrosion → electric plating lead; optimal formula: (1 NaOH 25-40g / L) electric net Na3PO410-20g / L, and Na2CO3 20-25g / L NaCl2-3g / L, and additive trace; (2) activation H2SO480-100g / L, HCl20-30g / L of NaCl 10 -20g / L, buffering salts of 40 ~ 50g / L, the additive trace amounts; (3) lead-plated Pb (Ac) 2150g / L, and HF160g / L, and H3BO320g / L gelatin 1g / L, and the dispersing agent A1G / L, and stabilizers B 1g / L, current density 1A/dm2, temperature 40 ° C. Lead plating layer preparation process in accordance with the thesis, and its appearance, the surface and cross section morphology and energy spectrum analysis, combined with the strength, corrosion resistance and performance testing. The results show that the thesis process in the aluminum surface prepared surface is smooth, uniform, dense, bubble-free preparation of the light grid and anode materials, preliminary validation suitable for lead-acid batteries with lead plating aluminum substrate binding force . Plating solution stability, high yield, low energy consumption, pollution, simple operation, low cost, easy to achieve industrialization. The paper further studied directly in the aluminum surface plating lead after deposition of lead dioxide layer. Since the lead dioxide having a similar metal of good conductivity, the two crystalline forms of α-PbO2 and β-PbO2, wherein the α-PbO2 is orthorhombic crystal small and dense, but the corrosion resistance and the poor conductivity, and pure lead layer with good adhesion, good affinity with β-PbO2 coating middle layer, so the choice of the α-PbO2 in alkaline bath; β-PbO2 tetragonal rutile lattice crystalline large, corrosion resistance and conductivity is far superior to the α-PbO2, therefore be selected as the coating surface layer is obtained in an acidic bath. Α-PbO2 is plated under alkaline conditions, after the aluminum surface plated directly lead plated under acidic conditions, the β-PbO2 the process obtained Al/Pb/PbO2 composite grid material, the surface of the obtained composite coating is uniform, dense, and the substrate good adhesion. After accelerating anode life test, converted to general industrial anode life is 876.27 days, than Usually Pb02 anode material having a longer life of the anode; the measured cell voltage of 2.9-3.2V, the average current efficiency of 90%, better than the traditional lead-silver alloy anode materials; anodic polarization curves showed that the oxygen evolution potential of this composite grid material is much lower than pure stereotype oxygen evolution potential, Al/Pb/PbO2 composite grid material very suitable electrolytic anode material. In summary, the aluminum through chemical and electrochemical processing lead plating directly on the surface as well as the surface of the layer of lead, lead dioxide plating layer is a new direction in the study of the grid material, the development and application of this type of grid material has broad market prospects and a good social and economic benefits.
|