ELETTRODI A DIFFUSIONE DI GAS A BASE DI MISCELE DI POLIETERESOLFONE E CARBONIO

摘要

All electrocatalytic gas diffusion electrode for fuel cells and a process for its preparation is disclosed. The electrode comprises an anisotropic gas diffusion layer and a catalytic layer. The gas diffusion layer is made of a porous carbon matrix through which carbon particles and polyethersulfone 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 Ám and 300 Ám. The catalytic layer has thickness between 7 Ám and 50 Ám and a metal catalyst loading between 0.2 mg/cm2 and 0.5 mg/cm2.