Patent ID: 11870038
Assignee: AESC JAPAN LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  G  Y | IPC G  H

Claim 0:
1. A method of determining whether a lithium-ion secondary battery is a quality product or a defective unit, the method comprising:
an initial charging step of charging the lithium-ion secondary battery, which has not been subjected to an initial charging, under a condition in which a viscosity of an electrolytic solution is equal to or higher than 6.0 mPa·s;
an aging step of leaving the lithium-ion secondary battery subjected to the initial charging step under a condition in which the viscosity of the electrolytic solution is equal to or lower than 4.5 mPa·s after the initial charging step;
a sorting step of measuring a voltage drop quantity of the lithium-ion secondary battery after or during the aging step, and comparing the voltage drop quantity with a predetermined reference value to sort out a lithium-ion secondary battery;
a determining step of determining that the lithium-ion secondary battery subjected to said sorting step is the quality product when the voltage drop quantity is less than the predetermined reference value; and
a determining step of determining that the lithium-ion secondary battery subjected to said sorting step is the defective unit when the voltage drop quantity is equal to or greater than the predetermined reference value.