Power evolution of fuel cell stack driven by anode gas diffusion layer degradation

Recent research has revealed that gas diffusion layer degradation has a crucial effect on fuel cell stack power density evolution. There have been several investigations focused on the influence of cathode gas diffusion layer degradation on stack performance. However, the degradation behavior and contribution of the anode gas diffusion layer on stack output power remain to be studied. Here, the 1000 h durability test of a stack was conducted under the New European Driving Cycle condition, and the effect of anode gas diffusion layer failure on the stack output power was evaluated. Carbon corrosion is the main attenuation characteristic of the anode gas diffusion layer, which significantly reduces its mechanical strength, and decreased the support capacity of the anode gas diffusion layer. Moreover, carbon corrosion also leads to exposure of new hydrophilic surfaces, reducing the hydrophobicity of the gas diffusion layer. In addition, the loss of hydrophobic agents is also one of the main characteristics of anode gas diffusion layer attenuation, which is the main reason for hydrophobicity loss. The decreased hydrophobicity will significantly improve the water retention capacity, and reduce the back diffusion of cathode water. As a result, mass transfer resistance will increase at a high current density. In conclusion, we verified the crucial impact of anode gas diffusion layer on cell output power density, and provide a new idea for the stack power attenuation investigation.

Automated summary

Recent research has shown that the degradation of the anode gas diffusion layer has a significant impact on the output power density of fuel cell stacks. This degradation is mainly due to carbon corrosion, which reduces mechanical strength, support capacity, and hydrophobicity of the layer. The decrease in hydrophobicity leads to increased water retention capacity and decreased back diffusion of cathode water.