| abstract |
A method for diagnosing deterioration of a secondary battery with high accuracy. A method for diagnosing deterioration of a secondary battery having an electrode element including a positive electrode and a negative electrode facing each other, wherein ultrasonic waves are irradiated to a plurality of positions on the surface of the electrode element and transmitted through the electrode element. Step S1 for measuring the transmission intensity of the battery, Step S2 for calculating a predetermined index representing the characteristics of the distribution based on the measured distribution of the transmission intensity, and comparing the index with a reference value to obtain a secondary battery. Step S3 for diagnosing the deterioration of [Selection] Figure 3 |