| 摘要 |
PURPOSE: To prevent generation of defects peculiar in a thin type battery by making the ratio of the thickness of separator to the total thickness of the battery over a specific value, 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 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 in a specified form, positioned opposingly while separators of an electrolytic solution absorbent 4 consisting of a fine porous polypropylene film 3 and a polypropylene non-woven cloth are interposed, and are put together in a single piece. At this time, the ratio of the separator thickness to the total thickness of the battery is made over 0.7 so that the outer can is hindered from deformation, which prevents poor contacting with the active material located internally, to lead to prevention of the charge/ discharge performance from deterioration. |
