Battery Impedance Modeling and Comprehensive Comparisons of State-Of-The-Art Cylindrical 18650 Battery Cells considering Cells' Price, Impedance, Specific Energy and C-Rate

Paper i proceeding, 2021

Within different areas of research and development of battery cells and systems, it is necessary to include electrical models of battery cells in simulations to reflect batteries' behavior. Linear or nonlinear electrical equivalent circuit models are commonly used for this purpose, such as the Warburg impedance and the three RC-pair model. In this paper, various protected and unprotected commercially available cylindrical (18650), state-of-the-art lithium-ion battery cells are considered. Their impedance parameters, according to the aforementioned models, are estimated using electrochemical impedance spectroscopies. Furthermore, the selected battery cells are comprehensively compared in terms of their price, impedance, specific energy and C-rate. Therefore, this paper provides a brief but comprehensive battery parameter library, which should assist battery system designers or power electronic engineers to conduct battery simulations and, thus, to properly choose battery cells with respect to application specific requirements.