Patent ID: 8610408
Filing Date: 2013-12-17
Classification: H01M,Y02E,Y02P

Abstract:
1. A method for charging a lithium ion secondary battery which comprises: a power generation element including a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte; a case accommodating the power generation element and having an opening; and a sealing plate sealing the opening of the case, the sealing plate having an external terminal of the positive electrode or the negative electrode, and an internal terminal electrically connected to the positive electrode or the negative electrode, the internal terminal and the external terminal being connected to each other and having an electrical resistance therebetween of 0.1 to 2 mΩ, the charging method comprising: (i) two or more constant-current charging steps in each of which the secondary battery is charged at a constant charge current and which are performed until a charge voltage reaches an end-of-charge voltage Ecsf; and (ii) a constant-voltage charging step which is performed after the charge voltage has reached the end-of-charge voltage Ecsf and in which the secondary battery is charged at the end-of-charge voltage Ecsf until a charge current drops to a predetermined current, the two or more constant-current charging steps including: (a) a constant-current charging in which the secondary battery is charged at a current Ic( (b) a constant-current charging which is performed after the charge voltage has reached the target voltage Ecs(