Abstract
Lithium ion battery is generally used in mobile devices for its advantages such as easy downsizing and weight saving due to high energy density. If there were short circuit points in the battery, the abnormal heating occurred for higher energy density than conventional batteries. It is necessary to identify the short circuit parts in Lithium ion battery. However, it is difficult to clarify the micro abnormal part in the battery by diagnosis imaging such as X-ray inspection. Therefore, a new technique of localization of short circuit part has been developed by using inverse analysis of the electromagnetic field around the battery. This method can inspect the short circuit part in the battery by estimating the electric current value at the arbitrary point from data of the magnetic field around the battery. Because the technique is nondestructive inspection and able to quantitatively evaluate, it can be expected to reduce the inspection cost and to improve the detection accuracy of short circuit in the battery. In this report, the effectiveness of this method was demonstrated through the analytical results in which the short circuit parts was identified from the magnetic flux density measured around the specimen that simulated the battery with short circuit by using the magnetic sensor.
