TFP's carbon nonwoven is widely utilised as a substrate for the GDL, a critical component of the MEA which is the heart of the fuel cell. The GDL forms the basis of both the anode and cathode, and is responsible for water management, the transport of reactants, electricity and heat, as well as providing structural support to the assembly.
The GDL must be both electrically and thermally conductive to allow current flow, and have a suitable pore structure to optimise mass transport. The structure must also exhibit the correct balance of hydrophobicity, to manage the movement of water and gases in the MEA. This latter property is critical to the efficient operation of the cell; if the GDL is too wet during operation the by-product (water) is not being effectively removed, flooding may occur and reactant gas movement is impeded. Equally, if the GDL is too dry then the membrane will dry out causing higher resistance. In both cases the performance of the cell is reduced.