SEALING PART AND BATTERY

Abstract

The invention proposes a sealing device that demonstrates both the effectiveness of preventing penetration and leakage of electrolyte solution and the effectiveness of reducing the failure rate of the sealing device. The sealing device is for batteries containing aqueous electrolyte solution; the material of the sealing device consists of an elastomer; the ratio cp R of the sealing device when fitted is greater than or equal to 50%; and the sealing device satisfies Eb > a X pb, where Eb is the elongation at break of the material of the sealing device as measured according to standard J1S K 6251, β is the elongation ratio of the cross-section, a = 6.919 XR - 2.066, and b = 2.278 XR - 1.767.