Method of making electrodes for electrochemical fuel cells

In preparing a fluid diffusion electrode, typical methods include applying a catalyst ink to a fluid diffusion layer, drying the catalyst ink and hot-pressing the coated fluid diffusion layer to produce a fluid diffusion electrode. In the present application, unexpected improvements in the smoothness of the resulting electrode have been observed by drying the catalyst ink during compaction. To assist with drying the catalyst layer, the compacting step may be performed at elevated temperatures. In some embodiments, a release sheet may be applied to the catalyst layer prior to compaction. In addition or alternatively, partial drying of the catalyst layer may occur prior to compaction.