| 摘要 |
PROBLEM TO BE SOLVED: To secure the proper operation of an explosion-proof mechanism, and simultaneously prevent the sealing performance of a battery can from being degraded in the spiral type lithium battery equipped with the explosion- proof mechanism and a PTC element. SOLUTION: An annular resin ring 10 which is identical in outer diameter to the outer diameter of a rupture disc 11, and is thinner in thickness than the thickness of a PTC element 9, is placed over the upper side of the rupture disc 11 in a state that the aforesaid ring is circumscribed with the PTC element. This constitution thereby allows the center of the PTC element to agree with the center of the rupture disc 11 without fail, and also make possible a situation that the thin wall part 11b of the rupture disc 11 is covered by the PTC element, to be avoided. Besides, a gap between a positive electrode terminal 7 and the rupture disc 11 can be filled in by a resinous ring 10. |
