MATLAB-Based Analysis of Water Concentration in Electrochemical Hydrogen Compressor Components

An electrochemical hydrogen compressor (EHC) can compress hydrogen via electrochemical reactions. Unlike polymer electrolyte membrane fuel cells, EHC exhibits the unique characteristic of not generating water from the cathode catalyst, leading to continuous dehydration of the polymer electrolyte membrane (PEM) due to electro-osmotic drag (EOD) during operation. Drying of the PEM causes an increase in ohmic resistance, so the PEM must be sufficiently hydrated and continuous water management is required. Based on the recorded temperature, humidity, and current density during the EHC operation, a MATLAB program was developed to calculate the water concentration at the interfaces of the EHC components (channel, gas diffusion layer, and PEM). Analysis of the results revealed a significant decrease in the PEM during electrolysis, particularly when a high voltage was applied to the EHC. It was confirmed that the anode side of the PEM experienced dehydration due to a substantial EOD, leading to a decrease in the water concentration. Conversely, the cathode side showed an increase in the water concentration, indicating a higher likelihood of water flooding.