Electrochemical cell having a self-regulating gas diffusion layer

摘要

The invention relates to an electrochemical cell having an electrode with a catalyst layer and a gas diffusion layer. The cell also includes a mass flow field for directing fluid to and away from the electrode. An additional gas diffusion layer is disposed between the gas diffusion layer and the flow field. This increases the diffusion resistance of the fluid. The electrochemical cell of the present invention is particularly useful in a process for electrochemically converting anhydrous hydrogen halide to essentially dry halogen gas, where it is necessary to control and increase limiting current. It is also possible to use the additional gas diffusion layer in an aqueous process electrochemical cell.