Embedded fiber sensing-enabled multi state joint observation of smart lithium-ion battery based on distributed thermal modeling

Real-time and accurate monitoring of the operating status is a key requirement to ensure the safe and reliable operation of lithium-ion batteries (LIBs). Existing studies focus on designing complex algorithms to optimize monitoring performance using highly limited measurements. (i.e. current, terminal voltage and surface temperature). However, the lack of new approaches for obtaining more comprehensive information, particularly inside LIB cells, poses a significant challenge to achieving refined monitoring of LIBs. To remedy this deficiency, this study presents a distributed thermal model-based approach for multistate observation, enabled by a novel smart battery design with the capability of self-sensing temperature distribution. In particular, the proposed novel smart battery actively integrates distributed fiber optical sensor internally and externally within the cylindrical LIB cell, enabling high-resolution measurements of its internal and surface temperatures in real time. Subsequently, a novel heat-generation enhanced cascaded distributed thermal model is developed to fully perceive the electrical and thermal behaviors of the smart LIB cell combining with a low-order observer, thereby achieving joint estimation of the heat generation rate, axial heat generation distribution, state of charge and health state in real time. Experimental results show that the novel smart LIB-based estimation framework outperforms existing electrical model-based methods in terms of accuracy and reliability, highlighting its considerable potential in enhancing the safety and reliability of practical applications, including electric vehicles, energy storage systems, and consumer electronics.