The invention relates to a
gas diffusion layer with a gradient hole structure for fuel batteries and a preparation method and applications thereof. The
gas diffusion layer consists of a
macroporous carbon-based support body and a micro-
porous layer which are overlapped, wherein the material of the micro-
porous layer is embedded in the
macroporous carbon-based support body from one side, far from the flow field of a battery, of the
macroporous carbon-based support body to form a transitional hole layer; the transitional hole layer is composed of the material of the micro-
porous layer and the
fiber of the macroporous carbon-based support body and is obtained by embedding the material of the micro-porous layer in the side, far from the flow field of a battery, of the macroporous carbon-based support body; and the curvature of reaction
gas transfer from the side next to the flow field to the side next to a catalyst layer in the
gas diffusion layer increases gradiently and the air permeability gradually reduces from 4-10s / 100ml to 100-900s / 100ml. By adopting the gas
diffusion layer with the structure, the
mass transfer curvatures of water and the gas in the gas
diffusion layer (GDL) can be effectively increased, the transfer path of the product-water can be prolonged and
liquid water in the battery can be maintained; and the gas
diffusion layer is particularly suitable for fuel batteries working under low
humidity and the cathodes of alkaline fuel batteries.