SECONDARY BATTERY DIAGNOSIS SYSTEM

To provide a secondary battery diagnosis system which is applied to a lithium-icon battery having an anode that includes two kinds of active materials, for assessing a change of the utilization rate of the anode active materials with good accuracy and having it reflected in a charge-discharge condition, thereby improving the useful life of the battery.SOLUTION: Provided is a secondary battery diagnosis system comprising a calculation unit for acquiring the operation data of a lithium-ion battery having an anode that includes two kinds of active materials and deriving the degradation feature quantity of the lithium-ion battery that includes at least the utilization rate (m) for each active material; and a control unit for updating the operation condition of the lithium-ion battery on the basis of the degradation feature quantity derived by the calculation unit. The calculation unit executes: a first step of deriving the charge rate dependency of a battery capacity and a function group pertaining to the distribution state of time constant in a voltage relaxation process, on the basis of the operation data of the lithium-ion battery; and a second step of deriving a utilization rate (m) for each active material, using the charge rate dependency and the function group obtained in the first step.SELECTED DRAWING: Figure 8 【課題】２種類の活物質を含む負極を有するリチウムイオン電池に適用した二次電池診断システムであって、負極の活物質の利用率の変化を精度よく判定し、充放電条件へ反映させることで、電池の寿命向上を実現する手法の提供を目的とする。【解決手段】二種類の活物質を含んだ負極を有するリチウムイオン電池の運用データを取得し、少なくとも活物質毎の利用率（ｍ）を含むリチウムイオン電池の劣化特徴量を導出する算出部と、算出部で導出した劣化特徴量に基づいてリチウムイオン電池の運用条件を更新する制御部と、を有する二次電池診断システムであって、算出部が、リチウムイオン電池の運用データに基づいて、電池容量の充電率依存性と、電圧の緩和過程の時定数の分布状態に関する関数群とを導出する第一の工程と、第一の工程で得た電池容量の充電率依存性及び関数群を用いて、活物質毎の利用率（ｍ）を導出する第二の工程と、を実行する。【選択図】図８