| 摘要 |
A secondary battery is provided to prevent water permeability through a case as well as a sealing part by forming a PTFE coating layer on the whole surface of a battery and to improve long-term storage due to excellent durability and sealability. A secondary battery(101) has a structure of inserting a electrode assembly inside a battery case of laminated sheet including a metal layer and resin layer, and thermally fusing it. A consecutive PTFE(polytetrafluoroethylene) layer is coated on the whole surface of a battery, including the sealing part of the outer circumference of a battery case formed by heat sealing, excluding electrode terminals(400, 410). The PTFE coating layer is obtained by dipping the battery cell accommodating the electrode assembly in the battery case in the PTFE-containing solution(610) and drying the battery cell. |
