Safety Monitoring Standards for Fiber Optic Sensing in New Energy Batteries

••Optical fiber sensing technologies used for batteries are comprehensively summarized and analyzed.••••Optical fiber sensing technologies used for batteries are comprehensively summarized and analyzed.••Recent advances in measuring key parameters are presented to address the critical issues for battery health monitoring.••The outlook for the future development and application of optical fiber sensing in battery monitoring is presented.With the proposal of a “smart battery,” real-time sensing by rechargeable batteries has become progressively more important in both fundamental research and practical applications. However, many traditional sensing technologies suffer from low sensitivity, large size, and electromagnetic interference problems, rendering them unusable in the harsh a. Optical fiber sensingRechargeable batteryReal-time sensingHealth monitoringRechargeable batteries have developed rapidly in the past several decades, becoming widely used in consumer electronics, electric vehicles, and large-scale energy storage systems [,,, ]. In recent years, electric vehicles have shown explosive growth, with global sales of about 6.5 million in 2021, which are expected to double in the next few years. In the switch from fossil fuels to renewable energy, reliable energy storage stations have become very important to the power grid for peak-load shifting. Rechargeable batteries are considered ideal electrochemical devices for large-scale energy storage stations [,, ]. Various rechargeable battery technologies, such as lead–acid batteries, lithium-ion batteries [9,10], sodium-ion batteries [,, ], and flow batteries [,, [1. Temperature is a crucial parameter in both single batteries and large battery packs, and it is highly related to battery health and safety. Cycling batteries often behave differently at different temperatures, and the appropriate temperature range can ensure they exhibit better performance. Moreover, in large battery modules/packs, temperature significantly affects the batteries' SOH, since different temperatures may trigger different aging rates and affect the batteries' performance consistency. If thermal runaway occurs, a flame or explosion may result [47,48]. Thus, temperature sensing technologies are essential for monitoring the health and ensuring the safety of batteries.The temperature sensors presently used in BMS are mainly thermo-resistive sensor.