Temperature field monitoring of lithium battery pack based on double-clad fiber Bragg grating sensor

Lithium-ion battery is one of the most versatile energy storage technologies today, and the reliability andsafety of lithium battery have always been the target pursued by the industry all the time, so it is particularlyimportant to accurately monitor the safety status of the battery. Actually, the ultimate cause of all lithiumbattery safety problems lies in the thermal runaway inside the lithium battery. In order to overcome the currentproblems of temperature measurement systems, such as low accuracy and insufficient stability for long-timeoperation at relatively high temperature, a temperature monitoring system of quasi-distributed lithium batterybased on double clad Fiber Bragg Grating (FBG) is proposed in this work. After the monitoring of thetemperature field and bulge deformation of 18650 lithium battery pack by building 4 channels and 16 doubleclad FBG points to monitor the temperature field and bulge deformation of 18650 lithium battery pack, theresults show that the points with abnormal temperature rise caused by short circuit and other problems can beaccurately determined under the temperature of 0-450 degrees C, with the corresponding temperature sensitivity of10 pm/degrees C, and the resolution of 0.1 degrees C. The double clad FBG attached to the surface of the lithium batteryshell can also monitor the bulge deformation on the surface of the battery shell, and its longitudinal pressuremodification sensitivity is up to 142 pm/N. The temperature field monitoring system of quasi-distributedlithium battery pack based on double clad FBG in this paper can not only ensure high-precision temperatureand deformation measurement, but also have good stability and anti-interference ability, which shows that theresearch work in this paper is expected to provide a reliable theoretical and experimental basis for the safetymonitoring and use of lithium battery pack.

Automated summary

This paper proposes a temperature monitoring system for quasi-distributed lithium battery based on double clad Fiber Bragg Grating (FBG), which can accurately measure the temperature field and bulge deformation of the lithium battery pack. The system has high precision, good stability, and anti-interference capability.