Correlating phase transition with heat generation through calorimetric data

Abstract

Despite the widespread utilization of Lithium-ion batteries (LIBs), concerns regarding safety during operation persist owing to accidents and potential risks of fires and explosions. To comprehend the thermal dynamics that underlie severe LIB incidents, calorimetry tests have been prevalently employed for over three decades to examine the exothermic/endothermic behavior, reaction kinetics, and thermal interactions among LIB materials. There exists a substantial volume of calorimetry test results on various LIB electrodes, electrolytes, and other components. However, this data showcases low consistency, yielding an unreliable database that obstructs a thorough understanding of LIB thermal behavior. In this research, a comparative analysis of differential scanning calorimetry (DSC) results from materials utilized in the most commercialized LIB systems is conducted. The analysis unveils notable discrepancies in DSC data amassed by different researchers, identifies five predominant causes of data inconsistency, proposes a standardized DSC operational procedure, and generates a set of self-consistent data. Subsequently, an intrinsic safety spectrum is delineated and compared with X-ray diffraction (XRD) outcomes to elucidate the correlation between the crystal lattice structure and the thermal behavior of the material. This work aids in the formation of a comparative DSC database, utilizing the vast but inconsistent literature data. Moreover, it clarifies the linkage between the material structure and thermal behavior, facilitating data-driven thermal analysis of LIBs.