Real-Time Monitoring of Temperature Field Distribution of Three-Element LiB Lithium Battery Using FBG Arrays

Temperature has a significant impact on the health and safety lifespan of lithium-ion batteries. In this article, we propose a monitoring network consisting of 32 fiber Bragg grating (FBG) sensors for real-time monitoring of the battery surface temperature. The temperature points measured by FBG sensors are used to construct the temperature distribution of the entire battery surface, enabling monitoring of the hotspots during the battery charging and discharging processes. The battery was subjected to 0.5-, 1-, and 1.5-C rate charging and discharging tests during the experiment. The results show that the battery surface temperature decreases gradually from the position close to the positive and negative electrode tabs to the position away from the positive and negative electrode tabs, and the temperature near the negative electrode tabs is the highest. The highest temperature rises during the first charging and discharging tests at 0.5-, 1-, and 1.5-C rates are 14.9 °C, 30.4 °C, and 38.4 °C, respectively. Additionally, the dynamic graph of the battery surface temperature change is constructed by the monitoring network composed of FBG sensors, which can reflect the real-time and intuitive distribution of the battery surface temperature during charging and discharging. Therefore, the proposed temperature monitoring network can accurately monitor the time and space of hotspots on the battery surface, improving the safety of battery operation.