Gas diffusion layer for proton exchange membrane fuel cell and preparation method thereof

A method for preparing a gas diffusion layer for a proton exchange membrane fuel cell, comprising;

• papermaking and drying a carbon fiber suspension composed of a fibrous binder, water, a dispersant, and carbon fibers with different aspect ratios to obtain a carbon fiber base paper, and then carbonizing and graphitizing under a protection of nitrogen or an inert gas to obtain the gas diffusion layer for the proton exchange membrane fuel cell;
• wherein the fibrous binder is a composite fiber or a blend fiber composed of a phenolic resin and other resin;
• wherein the other resin is one or more selected from the group consisting of polyvinyl alcohol, polyvinyl formaldehyde, polyvinyl butyral, polyethylene and polypropylene;
• wherein a length of the carbon fibers is 0.5-20 mm, the aspect ratios of the carbon fibers ranges 100-3000, and a mass of carbon fibers with aspect ratios in an interval [100, 500) accounts for 0-10 wt % of a total mass of the carbon fibers, a mass of carbon fibers with aspect ratios in an interval [500, 1000) accounts for 60-84 wt % of the total mass of the carbon fibers, a mass of carbon fibers with aspect ratios in an interval [1000, 2000) accounts for 5-25 wt % of the total mass of the carbon fibers, and a mass of carbon fibers with aspect ratios in an interval [2000, 3000] accounts for 1-5 wt % of the total mass of the carbon fibers;
• wherein an amount of the carbon fibers in the carbon fiber suspension is 0.01-5 wt % of an amount of the water;
• wherein the fibrous binder has a diameter of 5-50 μm, a length of 3-10 mm, and a residual carbon rate of 6-50%, and a content of the fibrous binder in the carbon fiber base paper is 5-30 wt %;
• wherein the dispersant is polyethylene oxide or Tween 60, and an amount of the dispersant in the carbon fiber suspension is 0.05-1.5 wt % of the amount of water;
• and
• wherein a viscosity of a dispersion composed of the dispersant and the water is 100-2000 Pa·s in the carbon fiber suspension.