| 摘要 |
PURPOSE:To prevent electrolyte from permeating through a water-repellent layer to an air-diffusion paper by forming a recess in a positive electrode case such that the difference of inner diameter between the upper and lower sections will take a predetermined value. CONSTITUTION:A recess 23 is formed in a positive electrode case 21 such that the dimensional difference of inner diameter between the upper and lower sections will be 0-1.0mm. consequently, the sideface of the recess 23 in the positive electrode case 21 will be vertical or approximately vertical, and when containing an air-diffusion paper 24 in said recess 23, a slight gap will occur or no gas will occur between the recess and the air-diffusion paper. Consequently, permeation of electrolyte through a water-repellent layer due to crack occurred in the water-repellent layer can be prevented. |
