This work aims at the development of a battery model, which simulates the operating voltage U_(op) of a high power lithium-ion battery at varying operating conditions. U_(op) results from the open circuit voltage U_(OCV) and the sum of overvoltages η_i that exist when the battery is under load: U_(op) = U_(OCV) (T, SOC) + η_0 (T, SOC, I) + η_(CT,C) (T, SOC, I) + η_(CT/SEI,A)(T, SOC, I) + η_(Diff,A/C) (T, SOC, I) The open circuit voltage U_(OCV) is determined with a quasi-stationary method. The ohmic loss η_0 and the interface losses η_(CT,C) and η_(CT/SEI,A) are measured and separated by the application of electrochemical impedance spectroscopy measurements in the high and middle frequency range and a corresponding DRT-analysis. Using an equivalent circuit model (ECM) enables the quantification of those loss processes and provides their resistance and time constant which are required to calculate the overvoltage. The lithium solid state diffusion losses η_(Diff,A/C) are studied by a current interruption method in the time domain which is the method of choice in the low frequency range and which equally provides the resistance and the time constant of the process. Finally, a continuous discharge curve is simulated. The ECM also serves as a basis for physically motivated fractional identification methods which estimate the impedance parameters out of time domain data. These methods, in turn, can be used for online parametrization of the presented battery model.
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