| abstract |
Disclosed is a packaging material for a battery which is less prone to cracking and pinholes during molding and has excellent moldability. The packaging material for a battery has an r value of 0.9 or more calculated by the following formula by a tensile test, at least including a laminate in which a base layer, a metal layer, and a sealant layer are sequentially laminated. r value = log (W A / W B ) / log (t A / t B ) W A = (X AO + X A45 2 + X A90 ) / 4 B = W (X B0 + X 2 + X × B45 B90) / 4 X A0 , X A45 , and X A90 : The width of the test specimen taken in the 0 °, 45 ° and 90 ° directions in the plane before the tensile test, X B0 , X B45 , and X B90 : The width of the central portion of the tensile direction after tensile test of the test piece taken in the 0 °, 45 ° and 90 ° directions in the plane t A : thickness of test specimen before tensile test t B : thickness of test specimen after tensile test |