A novel gel polymer electrolyte cell for in-situ application of corrosion electrochemical techniques

• A novel gel-polymer electrolyte electrochemical (G-PE) cell has been developed.
• It has been tested for electrochemical impedance spectroscopy (EIS) measurements.
• EIS results are similar to those obtained using a liquid electrolyte cell.
• The cell has been satisfactorily used in field measurements on a bronze sculpture.

Electrochemical techniques, such as electrochemical impedance spectroscopy (EIS), are widely used for corrosion studies. However, their applicability to studies on metallic cultural heritage has been less spread due to the usual need of performing measurements in-situ on sculptures or monuments. This paper presents the development of a gel polymer electrolyte (G-PE) cell to overcome the difficulties associated with the use of liquid electrolytes for in-situ measurements. 5% agar has been employed to gelify a 0.3 M NaCl electrolyte. Laboratory comparison has demonstrated that gelification with agar does not affect EIS results in a significant way. A robust and convenient electrochemical cell has been fabricated using this G-PE and has been successfully applied to obtain EIS data from a bronze sculpture in the National Archaeological Museum in Madrid (Spain).