| 摘要 |
In the present invention, an electrode group (4), in which a positive electrode plate (1) and a negative electrode plate (2) are rolled together with an intervening separator (3), is housed in a battery case (5). An opening of the battery case (5) is sealed by a seal plate (10). The seal plate (10) is formed by stacking an upper metal plate (11), a valve element (12), and a lower metal plate (13). In the electrode group (4), an insulating plate (6) is disposed on the opening side of the battery case (5). The electrode plate of one pole of the electrode group (4) is connected to the lower metal plate (13) via a lead (8). A first opening (13a) and a second opening (6a) are formed in the lower metal plate (13) and the insulating plate (6). If S1 is defined as the area of the first opening (13a) and S2 is defined as the area of the second opening (6a), the value of S2/S1 is within the range of 1.8 to 3.3. |
