| 摘要 |
A positive active material for electric primary cells, such as are used in electronic watches, is formed from a powder composed at least partially of grains having cores of silver peroxide completely surrounded by a layer of monovalent silver oxide and covered with a thin surface layer of metallic silver. The remainder of the powder, if any, comprises monovalent silver oxide grains, also covered with a thin surface layer of metallic silver. A process for making the material includes adding a reducing agent such as hydrazine to a powder having grains of less than 50 microns in diameter of essentially pure silver peroxide and reducing the silver peroxide to the point at which a thin layer of metallic silver forms on the surface of each powder grain. This point can be detected by a substantial reduction in electrical resistivity of the powder and occurs when approximately one-half of the original powder remains as silver peroxide.
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