| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with a high degree of safety, which can be released quickly when the internal pressure has risen so that rupture, etc., will never happen. SOLUTION: A secondary battery has a rupture valve of such a structure that to its opening 2, a metal foil 3 is joined, and the foil 3 is ruptured with a rise of the internal pressure so as to release the pressure. Therein the condition 40<=K<=350 should be met, where K is the quotient obtained by dividing the battery internal capacity in cm<3> by the area of the opening 2 in cm<2> . By establishing a proper K value, the rupture valve is actuated quickly when the internal pressure has attained the specified value, and a gas release is conducted. The metal foil is fabricated by the electroforming method, marking method, clad method, etc., and preferably the surface should be coated with a fluorine series waterproof agent. |
