Operando Battery Monitoring: Lab‐on‐Fiber Electrochemical Sensing Technologies

Abstract Success in the development of next‐generation rechargeable batteries is attained by achieving low cost, high energy density, and long cycling life. Battery optimization is challenging due to the complicated processes involving material selection and optimal utilization of cell components. Battery performance and status during the charging/discharging cycle depend on the complicated interdependence of battery design and operational parameters. Monitoring techniques must be able to detangle the hidden high‐value information, including states of charge, health estimations, and operational guidance, as well as provide non‐electrochemical early failure indicators. Fiber–optic battery monitoring methods, which are advantageous because of their low cost, compactness, remote sensing capabilities, and simple integration without interfering with internal chemistry, are recently reported. The convergence of fiber optic technology and smart battery platforms promises to revolutionize the industry. The introduction of electrochemical lab‐on‐fiber sensing technology to continuously operando monitor the performance, health, and safety status of batteries will promote more reliable energy storage systems. This review highlights recent advancements in, and associated benefits of, electrochemical fiber grating battery sensing. This powerful sensing technology's potential to make possible the next generation of sustainable energy storage, and discuss future directions for improving battery sustainability is showcased.