| 摘要 |
PURPOSE: To prevent generation of defects in a secondary battery caused by embodying in a thin construction by making the rate of volume maintenance over a specific value, wherein the rate is associated with charge and discharge of a positive electrode black mix and a negative electrode black mix, and thereby hindering the outer can from deformation. CONSTITUTION: A coin type secondary battery has a can bottom area of 7cm<2> or more, and a positive electrode black mix 1 and a negative electrode black mix 2 are shaped in discs having 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 in a specified form, positioned as opposing with separators 3, 4 interposed, and put together in a single piece. At this time, the flatness of the plane portion of the can bottom surface 10 is maintained by setting over 33 the rate of volume maintenance associated with charge and discharge of the positive and negative electrodes, and thereby 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. |
