Abstract

Solid conducting polymer electrolyte system, nano crystalline polyethylene oxide (PEO) complexed with sodium bicarbonate (NaHCO₃) salt was prepared by sol gel-technique. Several experimental techniques such as IR, composition dependence conductivity and temperature dependence conductivity in the temperature range of 303 to 368 K and transport number measurements were employed to characterize this polymer electrolyte system. The conductivity of the (PEO+NaHCO₃) electrolyte was found to be about 3times larger than that of pure PEO at room temperature. The transference data indicated that the charge transport in these polymer electrolyte systems is predominantly due to Na⁺. Using this nano crystalline polymer electrolyte system, a three PEM fuel cell stack have been fabricated and their open circuit voltage and I-V characteristics were studied for various gas concentrations. The open circuit voltage was found to be 1.10 V. A number of other cell parameters associated with the cell were evaluated and are reported in this paper.

Key words: Complex, conducting polymer electrolyte, ionic conductivity, transport number, polymer electrolyte membrane (PEM) fuel cell, current-voltage characteristics.