| 摘要 |
429,840. Batteries. FERGUSON BATTERY CO., Ltd., BAYES, J. R., SULMAN, E. H., River Plate House, South Place, Finsbury, London, and RUSSELL, N. W., 8, Fernleigh Court, Preston Road, Wembley, Middlesex. Dec. 7, 1933, No. 34461. [Class 53] A carbon electrode for an air-depolarized primary cell is made from a mixture of finely divided carbon and sulphur or ammonium sulphate. The mixture is fired to drive off the inorganic material, the porous body so formed being subsequently treated to reduce its permeability to liquids without affecting its permeability to air. The mixture may also contain cellulose such as wood flour and an organic binder such as sugar, molasses or glucose and starch having its granules burst such as wheat flour treated with boiling water, together with oil or water. Before firing the mixture may be formed into an electrode by moulding, pressing, extruding, &c., and dried. Firing may take place at 900 to 1000‹ C. under non-oxidizing conditions such as by packing the formed and dried bodies in sand, plumbago or gas retort carbon. The fired bodies, after cooling, are impregnated with a colloidal solution of silicic acid in trichlorethylene, carbon tetrachloride or other volatile solvent. The finely divided carbon used in the process may consist of bone and wood charcoal and graphite. The wood charcoal may be made from beech or birch and the graphite may be made by heating coke in an electric furnace. The wood flour is made from pine. Any skin left on the surface of the fired blocks is removed with sandpaper or emery. Before being treated with the silicic acid solution a portion of the length of each electrode may be dipped in a solution of paraffin wax in petrol. The remainder of the electrode is then immersed in a solution of ammonium chloride, and the first portion again immersed in molten paraffin wax. After drying, the electrode is fitted with tinned copper straps bolted or clamped to the electrode and the top of the electrode is again immersed in molten paraffin wax. The lower part is then treated with the solution of silicic acid. |
