| 摘要 |
PROBLEM TO BE SOLVED: To detect a defective circuit voltage in a shipment inspection so as to improve battery quality by connecting all the batteries in the corresponding lot in parallel after initial charging for matching open circuit voltages with each other. SOLUTION: A negative electrode using carbon applied to a copper foil as a negative electrode active material and a positive electrode using lithium cobaltate as a positive electrode active material are wounded several times via a separator into a roll-shaped group of components. Constant current charging is finished when a battery voltage reaches 4.1 V. Subsequently, all the batteries in the same production lot are connected in parallel so as to be left standing, and the battery voltage match each other. After again is carried out further, an open circuit voltage inspection is carried out and only a secondary battery with a defective open circuit voltage is rejected. In this way, variation of an open circuit voltage is reduced, and a secondary battery causing minor internal short circuit can be easily selected so as to be removed. Alternatively, matching of voltage may be carried out by performing parallel connection in aging or after aging. |
