| 摘要 |
PURPOSE:To reduce the variations in battery performances such as open-circuit voltage and internal resistance by using water glass as a binding agent for a positive mixture so as to cause the water glass to exhibit a moldability almost equal to that of polytetrafluoroethylene. CONSTITUTION:Water glass used as a binding agent in a positive mixture, is a concentrate aqueous solution of an alkali silicic-acid system glass. It has a molar composition of Na2O.nSiO2 (n ranges between 2.1 and 3.5), and contains 23-37% of SiO2, 6-18% of Na2O, less than 0.03-0.05% of Fe2O3 and less than 0.2% of insoluble matter. A positive mixture powder containing such water glass as a binding agent, is prepared by homogeneously mixing the water glass together with a positive active material such as manganese dioxide and a conductive auxiliary agent such as flake graphite in water, drying the mixture until its moisture content becomes around 18-17wt%, then granulating the mixture before the granulated mixture is formed into granular shapes, being followed by drying the granular mixture until is mixture content becomes around 0.5- 0.7wt% The thus prepared positive mixture powder is subjected to compression molding. |
