Gas diffusion layer and preparation method thereof

The invention provides a preparation method of a gas diffusion layer, which comprises the following steps: S01, printing slurry on pretreated bare carbon paper with a printing thickness of 10-80 [mu] m to obtain printed carbon paper; s02, spraying the spraying slurry on the slurry layer of the printing carbon paper in the step S01 to obtain sprayed carbon paper, the spraying time is 10 to 90 minutes, and the spraying thickness is 5 to 50 microns; and S03, carrying out heat treatment on the sprayed carbon paper in the step S02 for 5-60 minutes at the temperature of 200-500 DEG C to obtain the gas diffusion layer. The invention also provides the gas diffusion layer obtained by the preparation method. According to the preparation method, the gradient pore strategy is combined with different microporous layer preparation processes, and the pores in the gas diffusion layer are controlled to be in stepped distribution, so that the prepared gas diffusion layer has high moisture retention, and the problem of rapid pe