DIFFUSION LAYER FOR AN ELECTROCHEMICAL DEVICE AND METHOD FOR PRODUCING SUCH A DIFFUSION LAYER

摘要

A method for producing a diffusion layer of an electrochemical device, including: superimposition of multiple unidirectional webs of carbon filaments, filaments of each web positioned parallel with, and next to, one another; needle punching of the webs, breaking a proportion of the filaments such that broken portions of the filaments are tangled with other filaments of the webs; and cutting a proportion of the multiple unidirectional webs, the carbon filaments forming one electrically conducting outer surface of the diffusion layer. The needle punching is accomplished all the way through the multiple unidirectional webs, and/or through two principal opposite faces of the multiple unidirectional webs, and/or with an impact density against the multiple unidirectional webs of between approximately 100 and 300 impacts/cm².