External Electrode Temperature Monitoring of Lithium Iron Phosphate Batteries Based on Fiber Bragg Grating Sensors

Abstract

Lithium-ion (Li-ion) batteries have become a promising candidate for the electrical energy storage and power delivery solutions. Thermal management is a key tool to improve performance and safety of Lithium-ion batteries. Currently, the common method is using electric sensors to monitor the thermal behaviour of batteries. In this work, an optical fiber sensor was proposed for temperature measurement of cells. The proposed sensor consists of a metal ring and a fiber Bragg grating (FBG). The FBG sensor calibration test shows a good linearity and high sensitivity. The FBG sensors were gloved on the external electrodes to monitor the temperature variation during charge/discharge cycles, and the PT100 sensors were attached on the electrodes as a comparison. Comparison test illustrates the response of proposed FBG sensors has a good agreement with PT100 sensors. It provides that the proposed FBG sensor can be used to monitor the temperature variation of cells, which provides a promising tool to improve the thermal management and safety of Li-ion batteries.