| 摘要 |
Disclosed is a highly safe flat nonaqueous secondary battery. Specifically disclosed is a flat nonaqueous secondary battery (1) which comprises an outer case (2), a top sealing case (3) and an electrode group. The electrode group comprises a plurality of positive electrodes (5) and negative electrodes (6), and separators (7), said positive electrodes (5) and negative electrodes (6) being alternately laminated. Each positive electrode (5) comprises a main body portion (5a) (a positive electrode main body portion) and a collector tab (5b) (a positive electrode collector tab portion). Each separator (7) has a main portion (7a) that covers the main body portion (5a) of the positive electrode (5) and a pendent portion (7b) that covers the boundary portion between the main body portion (5a) and the collector tab (5b) of the positive electrode (5). With respect to the separators (7), the thermal shrinkage ratio in a direction A is larger than the thermal shrinkage ratio in a direction B that is perpendicular to the direction A. Each separator (7) is formed such that the direction B is generally parallel to the direction in which the collector tab (5b) of the positive electrode (5) protrudes from the main body portion (5a). At least a part of the peripheral portion of the main portion (7a) is provided with a bonding portion which is directly welded with another bonding portion. |
