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