Experimental and theoretical investigation of contact resistance in molten carbonate fuel cells

Abstract

This paper presents the results of experimental and theoretical investigations into the influence of contact force on contact resistance between the current collector and the porous nickel layer of a fuel cell electrode. Two main results were obtained: (i) the greater the force, the lower the contact resistance; (ii) above a certain level, the force applied to the electrode produces no significant change in contact resistance. An MCFC mathematical model was proposed to explain this phenomenon. The model resulted in simulated current-voltage curves obtained for various forces applied to the MCFC and a quantitative assessment of how this resistance affects the performance of the entire fuel cell rather than that of the electrode itself. The results of the study showed significant improvement in MCFC operating parameters due to contact resistance minimization when the compression force is increased to the level of 40 N/cm2, while further increase of the force beyond that point does not lead to any appreciable improvement in operating parameters.