Production of gas diffusion layers with cotton fibers for their use in fuel cells

The gas diffusion layer (GDL) is one of the most important parts of a proton exchange membrane fuel cell, that plays a key role transporting the current to the collector plates, distributing the reactant gases to the catalyst surface, and evacuating heat and water that is generated during the redox reactions inside the fuel cell. Speaking in terms of production cost, the GDL represents up to 45% of the total cost of the membrane electrode assembling (MEA). However, and despite its crucial role in a fuel cell, until recent years, the GDLs have not been studied with the same intensity as other MEA components, such as the catalyst or the proton exchange membrane. In this work, we present the production process, at laboratory scale, of a low cost GDL, using a non-woven paper-making process. A relevant aspect of this GDL is that up to 40% of their composition is natural cotton, despite which they present good electrical and thermal conductivity, high porosity, good pore morphology, high hydrophobicity as well as gas permeability. Furthermore, when the GDL with its optimum cotton content was tested in a single open cathode fuel cell, a good performance was obtained, which makes this GDL a promising candidate for its use in fuel cells.