Effects of electrolyte components on properties of Al alloy anode
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract: The effects of Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 on the properties of Al alloy anode were studied in alkaline medium at 25 ℃. The self-corrosion rate of Al alloy anode was studied by method of H2 immersed in aqueous medium, and the electrochemical properties of Al alloy anode were tested via galvanostatic discharge and dynamic potential methods. The results show that the self-corrosion rate of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium can be minimized by adding Na2SnO3, In(OH)3 and Na2SnO3+ In(OH)3. Na2SnO3, In(OH)3 and Na2SnO3+In(OH)3 make Al anodic potential shift positively in galvanostatic discharging. The most effective additive of Al alloy anode in 4 mol/L NaOH+3 mol/L NaAlO2 medium is 0.075 mol/L Na2SnO3+0.005 mol/L In(OH)3, integrating self-corrosion rate and electrochemical properties.
Key words: aluminum alloy anode; electrode potential; self-corrosion rate; alkaline medium