How does temperature affect the performance of a fuel cell?
The proton exchange membrane is one of the most advanced fuel cell designs. Hydrogen gas under pressure is forced through a catalyst, typically made of platinum, on the anode (negative) side of the fuel cell. At this catalyst, electrons are stripped from the hydrogen atoms and carried by an external electric circuit to the cathode (positive) side. The positively charged hydrogen ions (protons) then pass through the proton exchange membrane to the catalyst on the cathode side, where they react with oxygen and the electrons from the electric circuit to form water vapour (H2O) and heat. The electric circuit is used to do work, such as power a motor.
Temperature is a critical factor in the performance of a fuel cell, as it directly influences the chemical activity of the fuels and the effectiveness of the catalysts used in the system.1
- Low Temperatures: Cold conditions, such as 0 °C (32 °F), reduce the chemical activity of the fuels and the efficiency of the catalysts, which diminishes the fuel cell's capacity.1
- High Temperatures: While high temperatures improve activity factors, they can negatively impact the system by reducing the functional lifetime of essential components, including electrodes, sensors, blowers, and construction materials.1
Because of these trade-offs, each type of fuel cell is designed to operate within a specific temperature range. Significant deviations from this range typically result in a loss of both capacity and operational longevity. Furthermore, the choice of electrolyte is a primary determinant of a system's operating temperature; for instance, molten carbonate fuel cells require high temperatures of approximately 650 °C (1,200 °F) to function. Maintaining stable temperatures remains a significant engineering challenge in fuel cell design.1234