| 摘要 |
PURPOSE:To stabilize and improve the electric characteristics of an alkaline manganese battery under heavy load discharge, by limiting the porosity of a formed positive electrode compound consisting of manganese dioxide and finely comminuted graphite within a specific range. CONSTITUTION:As a positive electrode compound, there is employed a formed body 2 having a porosity in the range of 20-40% which has been prepared by molding under pressure a positive electrode compound of a mixture consisting principally of manganese dioxide and added with finely comminuted graphite. It is preferred to cause the formed body 2 to absorb 72-98% by volume of an electrolyte based on the total volume of all the pores and to limit the quantity of the electrolyte present in the formed body 2 within 75-110mul per gram of manganese dioxide. For example, 15g of flaky graphite is mixed with 85g of gamma-MnO2. Into a positive electrode can 1, 630mg of the mixture is placed and dry-pressed under a pressure of 2t/cm<2> into the formed body 2 having a diameter of 10.9mm., a thickness of 2.3mm. and a porosity of 32%. Into the body 2, an aqueous 45wt% potassium hydroxide solution is absorbed twice to fill up 90% by volume of the total volume of all the pores, thereby allowing 103mul of the electrolyte to be contained per gram of manganese dioxide. An alkaline battery has thus been prepared. |
