Characterization of Nafion solid polymer elecrolyte for an electrochemical sensor using scnanning probe microscopy and electrochemical impedance spectroscopy

Solid polymeric electrolyte Nafion film was studied using electrical and microscopic method based on scanning probe microscope (SPM) and electrochemical impedance spectroscopy (EIS). This thin film upon proper treatment was found to have ionic conductivity comparable to liquid electrolyte. Hence, to integrate an electrical device into a smaller sized platform, for example, electrochemical sensor or fuel cell, this material can be a best choice due to lower processing temperature, easy handling and less weight compared with other solid oxide electrolytes. Since it was based on the polymer constituent, however, the stability and lifetime during operation should be improved to outdo other competitors. Aiming at this goal, we have tried the electrical and structural characterization of Nafion film under hydration. Our SPM tool could easily reveal the significant change down to a nanometer scale of the structure and electrical property of Nafion film along the subsequent process and give the basic understanding of the effect on the performance and the long-term stability of the device.