| 摘要 |
PROBLEM TO BE SOLVED: To provide a secondary battery having an open-circuit voltage of 4.25 V or more and 4.50 V or less per unit cell in full charge state in which oxidation of a separator can be suppressed even at high-charged voltage. SOLUTION: The secondary battery is provided with a positive electrode 13, a negative electrode 14, an electrolyte 16, and a separator 15, and its open-circuit voltage per unit cell in the full-charge state is 4.25 V or more and 4.50 V or less. Since the separator 15 contains polyethylene superior in impregnation of the electrolyte 16 and polypropylene superior in oxidation resistance, impregnation ability of the electrolyte can be improved compared with the separator made of polypropylene, and oxidation of the separator 15 even at the open-circuit voltage in the range of 4.25 V or more and 4.50 V or less can be suppressed. COPYRIGHT: (C)2008,JPO&INPIT |
