First full cell parameterization of a commercial layered oxide/hard carbon sodium-ion 18650 battery cell for a physico-chemical model
Moritz Schütte, Hendrik Laufen, Daniel Luder, Heinrich Ditler, J. Kern, Sebastian Klick, M. Junker, Gereon Stahl, Fabian Frie, Dirk Uwe Sauer
Abstract
With first commercially available sodium-ion cells on the mass market, the interest in analyzing these cells is growing. Utilizing a physico-chemical model (PCM) allows access to internal states of the modeled battery cell and thus to gain a deeper understanding of underlying mechanisms within the battery. For the first time in literature, this work presents a full cell parameterization of a commercial sodium-ion battery featuring a layered oxide cathode and hard carbon anode for use in a physico-chemical model. Various methods were used to parameterize the cell. The laboratory based and partially literature based parameter set and the given PCM were validated using full cell measurements. The validation included a discharge with different C-rates, ranging from C/20 up to 5C. Simulations with the PCM resulted in a root mean squared error of 8.0 mV and 28.6 mV for C/20 and 5C, respectively. The state of charge interval based optimization was presented to improve the utilization of the PCM in understanding the underlying mechanisms within the battery and providing directive guidance for further laboratory work.