A discussion on the equilibrium potential and exchange current of hydride electrodes

✍ Scribed by Q.M. Yang; M. Ciureanu; D.H. Ryan; J.O. Ström-Olsen

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 564 KB
• Volume: 40
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(94)00352-2

✦ Synopsis

A theoretical treatment is presented to account for the dependence of the equilibrium potential and exchange current on the bulk hydrogen occupancy in hydride electrodes. The model is based upon considering the equilibrium between adsorbed and absorbed hydrogen at the interface. Several characteristic parameters can be obtained for the hydride electrode from the fit of the experimental data (c, and I,) to the theoretical concentration dependence: the maximum value of the storable hydrogen concentration, the solubility of H in the bulk at 1 atm, the equilibrium potential at X = 0.5, the symmetry coefficient for the electrochemical reaction. Also, it is possible to estimate the constant for the transfer through the interface, a parameter on which there are virtually very little information.

The model was found to fit very well the experimental data obtained on crystalline TiMn,,, . A discussion of the effect of lateral H-H interactions on the E, and I, values was made.