Health monitoring by optical fiber sensing technology for rechargeable batteries

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 and complicated electrochemical environments of batteries. The optical sensor is an alternative approach to realize multiple-parameter, multiple-point measurements simultaneously. Thus, it has garnered significant attention. Through analyzing these measured parameters, the state of interest can be decoded to monitor a battery's health. This review summarizes current progress in optical sensing techniques for batteries with respect to various sensing parameters, discussing the current limitations of optical fiber sensors as well as directions for their future development.