Irreversible Heat Generation based Electro-Thermal modeling and Its Experiment Validation of the 18650 Cylindrical Cells

In this paper, the proper internal resistance is shown as a heating factor for heat generation estimation of a lithium-ion battery. Electrical equivalent circuit model is introduced to verify irreversible heat parameter. Internal resistance is comprised of ohmic resistance and diffusion resistance. Three methods for determining resistance are introduced: 1) direct current resistance method; 2) electrochemical impedance spectroscopy method(EIS); 3) heating based resistance. By comparing resistances measured by three different methods, the summation of ohmic resistance and diffusion resistance is shown as the heating factor of a lithium-ion battery. Finally, it's feasibility as heating parameter is validated by comparing generated heat during 1C-rate discharging experiment and COMSOL simulation.