Galvanic Study of Zinc and Copper in Lithium Bromide Solutions at Different Temperatures

Galvanic corrosion of pure zinc coupled to pure copper was investigated in three different lithium bromide (LiBr) solutions (400 g/L, 700 g/L, and 850 g/L additive commercial solution) at different temperatures. The galvanic potential and the galvanic current were measured simultaneously by a zero-resistance ammeter (ZRA) at a rate of 2 Hz during a period of 24 h at 25°C, following a heating-cooling cycle from 25°C to 85°C at 0.5°C/min, during 2 h at 85°C, from 85°C to 25°C at 0.5°C/min and maintained at 25°C during the last 3 h. From the electrochemical data obtained and their subsequent statistical analysis in terms of mean values and standard deviation, it was concluded that copper-zinc coupling generated higher galvanic current in 400 g/L LiBr than in 700 g/L LiBr solution. The passivating character of the additives added to the commercial solution reduced the galvanic effect considerably. The temperature cycle imposed to the copper-zinc coupling showed that the galvanic current values at the end of the cycle were slightly higher than those measured initially.