Electrolyte Distribution of Phosphoric Acid Fuel Cells During Operation

Abstract

Phosphoric Acid Fuel Cells have excess electrolyte in each cell to compensate for acid loss during operation. We studied the distribution of excess electrolyte among the cell components during operation. For that purpose, we used small single cells to disassemble those cells immediately after operation. As a result of experiments, it is found that excess electrolyte almost exists in carbon components of the anode during operation. We suppose this is caused by migration of phosphoric acid ions from cathode to anode as a certain portion of the ion current during operation. This excess electrolyte movement to the anode does not have a bad effect upon the functions of each catalyst layer and matrix. But it is very important to consider this distribution of excess electrolyte to anode to design the amount of excess electrolyte and the capillary forces of cell the components.