Real-time mechanical and thermal monitoring of lithium batteries with PVDF-TrFE thin films integrated within the battery

Lithium battery cells typically have a sealed structure. Throughout the life cycle of such batteries, electric/chemical/force/thermal multi-field coupling interactions occur during the service process. Therefore, in situ characterization of the internal mechanics and temperature parameters of batteries is vital for managing their safety. In this study, a lithium-ion battery pressure/temperature monitoring micro thin-film sensor based on a flexible printed circuit anode current collector is formed by using a piezoelectric/pyroelectric poly (vinylidene fluoride-trifluoroethylene) material. The micro thin-film sensor is integrated within the battery and can monitor the mechanical and thermal damage inside the battery in real-time without interfering with the battery operation. The micro thin-film sensor prepared following this method provides sufficient early warning of battery failure and can significantly improve battery safety performance.