| 摘要 |
PURPOSE:To increase the penetration capability and retainability of phosphoric acid and adherence to an electrode by uniformly kneading an electrolyte retaining material comprising mixed particles containing silicon carbide and metal silicide, a binder, and a plasticizer, and forming a sheet, then extracting the plasticizer with a solvent. CONSTITUTION:A pair of gas diffusion electrodes comprising catalyst layers 2a, 2b obtained by applying carbon supported with platinum with water repellent polytetrafluoroethylene serving as a binder are formed on both sides of an electrolyte retaining matrix 3 in which phosphoric acid is retained. They are covered with electrode substrates 1a, 1b such as conductive carbon sheets to form a unit cell 4. The unit cell 4 is placed between separators 6 each of which has a large number of parallel gas supply grooves 5, and a plurality of these units are stacked. As a metal silicide for forming the electrolyte retaining matrix, TiSi2, CrSi2, ZrSi2, NbSi2, MoSi2, TaSi2, or WSi2 is used. Fluorocarbon resin is used as a binder, and dialkyl phthalate as a plasticizer. The content ot SiC is 30-80wt.% based on the matrix. |
