Non-aqueous electrolyte secondary battery evaluation device and non-aqueous electrolyte secondary battery evaluation method

摘要

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery evaluation device and evaluation method which can detect the elution of manganese when in actual use.SOLUTION: An evaluation device 100 for a lithium ion secondary battery 10 incorporating a manganese-containing cathode comprises a voltmeter 20 which measures the battery voltage of the lithium ion secondary battery 10 and a controller 50 which evaluates the lithium ion secondary battery 10 by detecting the elution of manganese from the cathode. On the basis of a decline per given hour of the voltage at the end of discharge time measured by the voltmeter 20 when the lithium ion secondary battery 10 is discharged at a predetermined charge rate De or more for a predetermined charge time Te or more, the controller 50 detects the presence of manganese elution, whereby it evaluates the lithium ion secondary battery 10.