| 摘要 |
361,164. Galvanic batteries ; alloys. JOHNSON, J. Y., 47, Lincoln's Inn Fields, London.-(I. G. Farbenindustrie Akt.-Ges. ; Frankfort-on-Main, Germany.) Dec. 24, 1930, No..38887. [Class 53.] Negative electrodes of porous iron for use in alkaline accumulators are strengthened by incorporating in the electrodes unattackable strips of iron-nickel alloy which may run across the electrodes parallel to the edges or may form a framework round the edges. The strips of alloy may be made by impregnating the edges or other parts of the electrode with a solution of a nickel salt such as the nitrate and then washing the plate with caustic alkali solution to precipitate nickel hydroxide in the impregnated parts. The plate is then heated in hydrogen or other reducing atmosphere to reduce the nickel hydroxide to metallic nickel which forms an alloy with the iron. The impregnation of the electrode in strips running across its face may be effected by covering the electrode with a plate having openings corresponding to the strips to be impregnated and then sucking first a solution of a nickel salt and then a solution of caustic alkali through the openings and through the parts of the electrode beneath the openings. In another method powdered iron is filled into a mould and the powder removed at the edges and in strips parallel to the edges and replaced by a mixture of 90 per cent of iron powder and 10 per cent of nickel powder. The mould is then heated to 650‹ C. until a coherent porous metal plate is obtained. The sintered plate is then further heated to 1100‹ C. to cause the nickel to alloy with the iron. The porous iron plate is preferably made from powdered iron obtained by the decomposition of iron carbonyl. The finished plate may be used as the negative electrode in an alkaline accumulator or the pores may be filled with active material such as cadmium oxide which may be introduced by impregnating the plates with a solution of a cadmium salt and precipitating cadmium hydroxide within the pores by caustic alkali solution. The Provisional Specification states that parts of the iron plates may be protected against attack by impregnating them with paraffin wax or similar substances. |
