METHOD FOR MANUFACTURING NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

PROBLEM TO BE SOLVED: To provide a method for manufacturing a reliable battery for a short time by permanently shortening a length of time required for a self discharge step.SOLUTION: A method for manufacturing a nonaqueous electrolyte secondary battery comprises the steps of: preparing an electrode body; constructing a battery assembly with the electrode body; charging the battery assembly to SOC 65% or more; aging the battery assembly at 40°C or higher for at least 5 hours; leaving the battery assembly; and causing the battery assembly to discharge by itself in a normal temperature region, followed by measuring a voltage drop. If a leaving time H during which the battery assembly is left in the step of leaving the battery assembly is within a predetermined normal leaving time, a leaving temperature T when the battery assembly is left in the step of leaving the battery assembly is made a predetermined regular set temperature. On the other hand, if the leaving time H is an excessively leaving time over the normal leaving time, the leaving temperature T is set to be higher than the regular set temperature according to the leaving time H in the step of leaving the battery assembly. 【課題】自己放電工程に要する時間を恒常的に短縮し、短時間で信頼性の高い電池を製造する方法を提供する。【解決手段】かかる製造方法は、以下の工程：電極体を準備する工程；上記電極体を用いて電池組立体を構築する工程；上記電池組立体をＳＯＣ６５％以上まで充電する工程；上記電池組立体を４０℃以上で少なくとも５時間エージングする工程；上記電池組立体を放置する工程；上記電池組立体を常温域で自己放電させて電圧降下量を計測する工程；を包含し、ここで、上記放置工程における放置時間Ｈが予め定められたノーマル放置時間内の場合は上記放置工程における放置温度Ｔを所定の平常設定温度とする一方、上記ノーマル放置時間を上回る超過放置時間の場合は上記放置工程における放置時間Ｈに応じて上記放置温度Ｔを上記平常設定温度よりも高く設定する。【選択図】図４