| 摘要 |
PURPOSE: A lithium ion secondary battery is provided which efficiently prevents the leakage of an organic electrolytic solution by improving the sealing condition of an electrode tap and an upper part and a lower part case and has improved charging and discharging property and life property. CONSTITUTION: The lithium ion secondary battery comprises: (i) a battery assembly(20) which is prepared by laminating a cathode plate, an anode plate and a separator and has electrode taps(23, 23') to induce generated electric current to the outside; (ii) a case(30) which comprises an upper case part(30a) and a lower case part(30b) and seals the battery assembly by joining the border of the upper case part to the lower case part with exposing a part of the electrode taps to the outside; and (iii) sealants(25, 25') which coat the certain area of the electrode taps in certain width and are interposed between the border of the upper case part and the border of the lower case part to prevent the leakage of an organic electrolytic solution and are made of ethylene-vinyl acetate copolymer. |
