Gas diffusion layer (GDL), as an important transmission component of gas, electricity and liquid, is usually composed of carbon paper, which needs hydrophobic treatment before it is applied in fuel cell. In the paper, ultrasonic dispersion technique is added to the traditional method of preparing hydrophobic carbon paper, and the effect of ultrasonic dispersion on the PTFE load in hydrophobic carbon paper is studied. The theoretical study shows that the ultrasonic dispersion increases the movement of the liquid, thus improving the diffusion performance of the liquid molecules. The experimental results show that compared with the hydrophobic performance of the original carbon paper, the hydrophobic carbon paper prepared by ultrasonic method improves the hydrophobic performance by 13.24%. However, there is no obvious relationship between the PTFE content of the carbon paper treated by ultrasonic dispersion and the hydrophobicity of the carbon paper surface. In addition, ultrasonic dispersion also has a great influence on the gas permeability of hydrophobic treated carbon paper, but the effect on the surface conductivity of carbon paper is not obvious. The results can provide a guidance for the preparation of hydrophobic carbon paper for fuel cells.

气体扩散层（GDL）作为气体、电力和液体的重要传输部件，通常由复写纸组成，在应用于燃料电池之前需要进行疏水处理。本文在传统的疏水碳纸制备方法中加入了超声波分散技术，研究了超声波分散对疏水碳纸中聚四氟乙烯负载量的影响。理论研究表明，超声分散增加了液体的运动，从而提高了液体分子的扩散性能。实验结果表明，与原碳纸的疏水性能相比，超声波法制备的疏水碳纸疏水性能提高了13.24%。然而，经超声波分散处理的复写纸的PTFE含量与复写纸表面疏水性无明显关系。此外，超声波分散对疏水处理过的碳纸的透气性也有很大影响，但对碳纸表面电导率的影响并不明显。研究结果可为燃料电池疏水碳纸的制备提供指导。