Corrections of Voltage Loss in Hydrogen-Oxygen Fuel Cells

Abstract

Normally, the Nernst voltage calculated from the concentration of the reaction gas in the flow channel is considered to be the ideal voltage (reversible voltage) of the hydrogen-oxygen fuel cell. The Nernst voltage loss in fuel cells in most of the current literature is thought to be due to the difference in concentration of reaction gas in the flow channel and concentration of reaction gas on the catalyst layer at the time as when the high net current density is generated. Based on the Butler−Volmer equation in the hydrogen-oxygen fuel cell, this paper demonstrates that Nernst voltage loss caused by concentration difference of reaction gas in the flow channel and reaction gas on the catalyst layer at equilibrium potential. According to the relationship between the current density and the concentration difference it can be proven that Nernst voltage loss does not exist in hydrogen-oxygen fuel cells because there is no concentration difference of reaction gas in the flow channel and on the catalytic layer at equilibrium potential when the net current density is zero.

Keywords

• nernst voltage
• activation loss
• concentration loss
• nernst voltage loss
• concentration overpotential
• equilibrium potential
• exchange current density
• net current density