| 摘要 |
PROBLEM TO BE SOLVED: To improve the storage capacity per electrode volumetric unit by dry-compressing spherical nickel hydroxide having high solid density and using the resultant nickel hydroxide as a cathode active material for this alkaline button battery. SOLUTION: The density of nickel hydroxide to be used for the cathode of this battery is controlled to be 3.3-3.9 g/cm<3> by a pycnometer measuring method, and the particle size is normally controlled to be 5-20μm, further preferably, 10-15μm. Normally, metal nickel, cobalt, graphite, and cobalt oxide are added as cathode additives with 1-5μm particle size and preferably, a powder plastic binder is additionally added. The mixture of these substances are granulated into a pellet with 100-1000μm particle size and then dry- compressed to give a positive electrode. By using the spherical nickel hydroxide with smooth surface, the filling density is improved as compared with that in the case nickel hydroxide with irregular shape is used. Moreover, it is preferable that a hydrogen storage alloy MnNi5 containing mixed metal is used for the negative electrode material. Further, a finely porous substance, having smaller pore diameter than the minimum particle size of the nickel hydroxide, is used as a separator. |
