| 摘要 |
PURPOSE: To prevent deterioration of the charging/discharging performance of a secondary battery by making the ratio of the degree of recession in the outer can to the area of can bottom over a specific value, thereby hindering the outer can from deformation, and preventing occurrence of poor contacting with an active material black mix located internally. CONSTITUTION: A coin type secondary battery has a can bottom area of 7cm<2> or more, and a positive electrode 1 and a negative electrode 2 in disc shape are given diameters as 70% and 80%, respectively, of the specified diameter of the battery, accommodated in a positive electrode can 5 and negative electrode can 7 made of stainless steel embodied in a specified shape, positioned opposingly with separators 3, 4 interposed, and put together in a single piece to accomplish the battery. At this time, the ratio of the degree of recession in the outer can to the area of can bottom is made over 0.0025/cm so that the outer can is hindered from deformation, which prevents poor contacting with the active material black mix located internally, to lead to prevention of the charge/discharge performance from deterioration. |
