초록 ▼

All electrocatalytic gas diffusion electrode for fuel cells and a process for its preparation is disclosed. The electrode comprises an anistropic gas diffusion layer and a catalytic layer. The gas diffusion layer is made of a porous carbon matrix through which carbon particles and poly(vinylidene) f

All electrocatalytic gas diffusion electrode for fuel cells and a process for its preparation is disclosed. The electrode comprises an anistropic gas diffusion layer and a catalytic layer. The gas diffusion layer is made of a porous carbon matrix through which carbon particles and poly(vinylidene) fluoride are distributed so that the matrix is homogeneously porous in a direction lateral to gas flow and asymmetrically porous to gases in the direction of the gas flow. The porosity of the gas diffusion layer decreases in the direction of gas flow. The catalytic layer is made of a coagulated ink suspension containing catalytic carbon particles and a thermoplastic polymer selected from polyethersulfone, poly(vinylidene fluoride) and sulfonated polysulfone and covers the small pore surface of the gas diffusion layer. The gas diffusion layer has a thickness between 50 .mu.m and 300 .mu.m. The catalytic layer has thickness between 7 .mu.m and 50 .mu.m and a metal catalyst loading between 0.2 mg/cm.sup.2 and 0.5 mg/cm.sup.2.

대표청구항 ▼

[ What is claimed is:] [1.] An electrocatalytic gas diffusion electrode for fuel cells comprised of:an anisotropic gas diffusion layer that is made of a porous carbon matrix through which carbon particles and poly(vinylidene fluoride) are distributed such that the matrix is homogeneously porous in a

[ What is claimed is:] [1.] An electrocatalytic gas diffusion electrode for fuel cells comprised of:an anisotropic gas diffusion layer that is made of a porous carbon matrix through which carbon particles and poly(vinylidene fluoride) are distributed such that the matrix is homogeneously porous in a direction lateral to gas flow and asymmetrically porous to gases in the direction of gas flow, said layer having first and second surfaces that are oppositely disposed to one another, gas permeating through said first surface and exiting said second surface during use of said electrode, the porosity of said gas diffusion layer decreasing from said first to said second surface in the direction of gas flow, said gas diffusion layer having a thickness between about 50 .mu.m and about 300 .mu.m, anda catalytic layer that is made of a coagulated ink suspension containing metal catalyst loaded carbon particles and a thermoplastic polymer, the catalytic layer covering the second surface of said gas diffusion layer, said catalytic layer having a thickness between about 7 .mu.m and about 50 .mu.m and a metal catalyst loading between about 0.1 mg/cm.sup.2 and about 0.5 mg/cm.sup.2.