Question

Explain the activation, ohmic, and mass-transport losses in the fuel cell. Then, explain how the performance of fuel cell can be increased.

Answer 1

*Activation Losses: They are caused by the slowness of the reactions taking place on the electrode surface.The decrease in voltage is because of the electrochemical reaction kinetics.

*Ohmic losses:They are caused due to the resistance in  the flow of ions in the electrolyte and electrons through the cell hardware and various interconnections. The corresponding voltage drop is proportional to current density, hence the term "ohmic losses.

*Mass-transport losses :They are caused due to the decrease in reactant concentration at the surface of the electrodes as fuel is used. At maximum (limiting) current, the concentration at the catalyst surface is practically zero, as the reactants are consumed as soon as they are supplied to the surface.

----->Please Find the below given graph:::::

INCREASE IN PERFORMANCE OF FUEL CELL ::::::::::::

-->Since fuel flow is controlled proportional to current, the fuel utilisation or current efficiency will remain constant with current. A fuel utilisation with a reasonable voltage efficiency-current characteristic is selected (For maximum overall efficiency the voltage and current efficiency should be nearly equal but a lesser voltage efficiency will give a compromise between power and efficiency).

-->A maximum design current is selected on the substantially linear part of the voltage-current characteristic. The crossing point determines the operating voltage. Since excess voltage is dropped at partial loads to maintain a constant AC voltage, the effective DC voltage and voltage efficiency are constant with current (up to the maximum design current).

#HOPE THIS WILL HELP YOU!!!!!!!

#THANK YOU!!!