摘要 |
The open end of a battery case (1) that houses an electrode assembly (14) is sealed with a sealing plate (3), the top of the sealing plate (3) is closed off with an insulating plate (11), and inside a concave section formed in the sealing plate (3), a positive electrode lead (12) that extends from a positive electrode plate of the electrode assembly (14) is connected in series to a thermal fuse (8) and a PTC element (9) and then to a positive electrode terminal (+). A two fold safety function is provided so that in the case of an external short-circuit across the positive and negative electrodes, excessive current is regulated by a rapid increase in the resistance of the PTC element (9) accompanying the temperature increase, whereas if a temperature increase occurs that cannot be regulated in this manner, the thermal fuse (8) fuses, breaking the circuit. <IMAGE> |