Synergistic effect of polyethylene glycol 600 and polysorbate 20 on corrosion inhibition of zinc anode in alkaline batteries

Abstract

Polyethylene glycol 600 (PEG 600) and polysorbate 20 (Tween 20) were used as a composite corrosion inhibitor of zinc in alkaline solution for the first time. The effects of the composite and individual inhibitors on corrosion inhibition of zinc were evaluated by weight-loss analysis and electrochemical methods including potentiodynamic, potentiostatic, and electrochemical impedance spectroscopic measurements. It was found that there was a synergistic effect between PEG 600 and Tween 20 on corrosion inhibition of zinc. The corrosion inhibition efficiency of the composite inhibitor, 500 ppm PEG 600 + 500 ppm Tween 20, was 89%, much higher than that of the individual inhibitor, 1000 ppm Tween 20 (71%) or 1000 ppm PEG 600 (55%). The battery (Zn/MnO2) discharge performance tests showed that the composite inhibitor reduced the self-discharge of zinc anode more effectively than the individual inhibitor. The synergistic mechanism between PEG 600 and Tween 20 was discussed.