| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a lithium ion secondary battery, by which a water content can be removed from inside a battery case of an assembly by a desired amount (i.e. a target value of a previously set decrease of water).SOLUTION: A method for manufacturing a lithium ion secondary battery comprises: the second step (S23) in which a value given by (Ps-Pk)×t1 is calculated by calculating a value of difference in vacuum degree by subtracting a reference vacuum degree Pk from a vacuum degree Ps in a battery case 110, which is measured at intervals of a fixed time t1 and multiplying the difference value by the fixed time t1 upon determination that a measurement of a vacuum degree in a battery case 110 has reached 100 Pa; the third step (S24) in which an integration value is calculated by integration of the value (Ps-Pk)×t1 calculated until the time; the fourth step (S25) in which a decrease in water is determined from the integration value determined in the third step based on correlation data grasped in advance; and the fifth step (S26) in which determination is made on whether or not the decrease in water determined in the fourth step has reached a preset threshold Th.SELECTED DRAWING: Figure 7 |
