摘要 |
1,199,426. Dry cell using heat-treated MnO 2 depolarizer. SOC. DES ACCUMULATEURS FIXES ET DE TRACTION. 29 Nov., 1967 [30 Nov., 1966], No. 54427/67. Heading H1B. A dry cell comprises a can-type anode, e.g. of zinc, a rod-like cathode disposed therein, e.g. of carbon, an electrolyte, a depolarizer mix around the cathode, and a separator between the depolarizer and the anode, the depolarizer mix being maintained in a state of compression and comprising particles of MnO 2 which have been heated in air in such a manner that the voltage of the cell is more constant during discharge than that of a similar cell using untreated MnO 2 . The MnO 2 particles may be prepared by heating rho or gamma MnO 2 particles in air at 250-450‹ C. a surface layer of beta MnO 2 is believed to be formed. The cell is made by making the can electrode and depolarizer body wider than is finally required, then reducing the diameter of the cell to the required value after assembling it. The electrolyte may be introduced subsequently. |