LITHIUM ION SECONDARY BATTERY

摘要

Provided are a lithium ion secondary battery which is prevented in the generation of a micro-rim formed when an electrolyte injection hole is sealed and the leakage of an electrolyte solution, and a cap assembly used in the battery. The lithium ion secondary battery(30) comprises a cap assembly(300) provided with a cap plate(310) having at least an electrolyte solution injection hole(312), wherein the electrolyte solution injection hole comprises at least a sealing gasket(362) in the upper inner side and is sealed with a sealing plate(360) located at the upper part of the sealing gasket. The sealing plate is made of a resin and is molten at a temperature of 90-100 deg.C. The battery comprises further a fixing pin(364) which is inserted into the sealing gasket to fix it.