Recently, the first commercial sodium-ion cells have become available for consumers. Given the exciting announcements by several producers of such battery cells [1], it is of great interest to analyze these first commercial sodium-ion cells in order to understand which materials are used, how these cells are designed, and how they perform in comparison with lithium-ion cells. In this poster, two types of commercially available sodium-ion battery cells (cylindrical 1.5 Ah 18650 and 3.5 Ah 26700 cells) are investigated regarding (i) their electrode chemistry by physicochemical ex situ (ante-mortem) studies, (ii) their thermal properties during discharge as a function of the applied C rate, (iii) the available specific energy as a function of anode coating thickness, and (iv) the cell impedance as a function of cathode coating area. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis of the 18650 cell reveal that the anode consists of hard carbon and the cathode of a NaNixFeyMnzO2 layered oxide. The data of the commercial sodium-ion cells are set into context with several types of commercial and pilot-line lithium-ion cells with different electrode chemistries [2-5], showing that the herein studied 18650 sodium-ion cells provide a comparable or even higher specific energy (~128 Wh kg-1) than that of graphite||LiFePO4 lithium-ion cells.

References
[1] A. Rudola, R. Sayers, C.J. Wright, J. Barker, Nat Energy 8 (2023) 215–218.
https://doi.org/10.1038/s41560-023-01215-w
[2] T. Waldmann, S. Rössler, M. Blessing, R. Schäfer, R.-G. Scurtu, W. Braunwarth,
M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 168 (2021) 90519.
https://doi.org/10.1149/1945-7111/ac208c
[3] M. Flügel, K. Richter, M. Wohlfahrt-Mehrens, T. Waldmann, J. Electrochem. Soc. 169 (2022) 50533. https://doi.org/10.1149/1945-7111/ac70af
[4] T. Waldmann, G. Bisle, B.-I. Hogg, S. Stumpp, M.A. Danzer, M. Kasper, P. Axmann, M. Wohlfahrt-Mehrens, J. Electrochem. Soc. 162 (2015) A921-A927. https://doi.org/10.1149/2.0561506jes
[5] C. Veth, D. Dragicevic, C. Merten, Journal of Power Sources 267 (2014) 760–769. https://doi.org/10.1016/j.jpowsour.2014.05.139