This application proposes a method, device, equipment, and medium for early warning of battery module and
cell expansion. The method includes simultaneously acquiring the surface temperature, composite stress, and
voltage signals of the target
cell through a flexible circuit board's acquisition terminal; calculating the thermodynamic deformation component based on the surface temperature and pre-stored material
thermal expansion coefficients, and performing a differential operation between the composite stress and this component to perform a first-level decoupling, thus removing interference from the physical
thermal expansion of the conductive
busbar and extracting pure mechanical stress parameters; determining the
cell's state characteristics based on the
voltage signal, obtaining a
reference stress value by calling a preset baseline, comparing the pure mechanical stress with the
reference stress to perform a second-level decoupling, thus removing interference from electrochemical expansion during charging and discharging and calculating an abnormal expansion force residual parameter; and performing real-time early warning monitoring of abnormal mechanical expansion states based on this parameter. This invention reduces the synchronization error of multi-dimensional
signal acquisition, achieves dual decoupling, and significantly improves the accuracy and timeliness of battery
thermal runaway early warning.