Available on-demand - F.EN07.06.18
Late News: Mixed-Anion Na-Hydroborates as New Class of Solid Electrolytes
Matteo Brighi1,Fabrizio Murgia1,Radovan Cerny1
University of Geneva1
Show Abstract
Li- and Na-based hydroborates are known for their high ion dynamic, leading to liquid-like cation mobility after an order-disorder phase transition, suggesting their use as solid electrolytes for all-solid batteries.[1,2] However this transition takes place at elevate temperature, outside the typical operation range of a conventional battery .[3–5]
A systematic study on Na-based closoborates and carba-closoborates has been conducted by means of anion mixing, in order to stabilize room temperature Na-conducting phases, relying on increased structural disorder. The effect of such mixing is the suppression of any phase transition, leading to six novel Na-conductors with a Na-conductivity close to 1 mS cm-1 at room temperature.
Due to the three-dimensional aromatic nature of the boron cage, closoborates are among the more robust available polyanions;[6,7] the six presented phases are indeed thermodynamically stable in the investigated temperature range 100 < T < 700 K, while depending from the mixture the electrochemical stability window varies from 3 to 4.1 V versus Na+/Na, allowing their implementation in high -voltage next generation solid-state batteries.[8]
The physical/electrochemical properties of this family will be presented, with particular remark to the non-Arrhenius conductivity behavior, arising from the ion-ion interaction. Their flexibility, in terms of operating voltage window, allowed also to check their compatibility towards different class of cathode materials such as NaCrO2[9,10], Na2Fe2(SO4)3[11] and Na3V2(PO4)2F3.
References:
[1] J. B. Varley, K. Kweon, P. Mehta, P. Shea, T. W. Heo, T. J. Udovic, V. Stavila, B. C. Wood, ACS Energy Lett. 2017, 2, 250.
[2] K. E. Kweon, J. B. Varley, P. Shea, N. Adelstein, P. Mehta, T. W. Heo, T. J. Udovic, V. Stavila, B. C. Wood, Chem. Mater. 2017, 29, 9142.
[3] T. J. Udovic, M. Matsuo, A. Unemoto, N. Verdal, V. Stavila, A. V. Skripov, J. J. Rush, H. Takamura, S. Orimo, Chem. Commun. 2014, 50, 3750.
[4] T. J. Udovic, M. Matsuo, W. S. Tang, H. Wu, V. Stavila, A. V. Soloninin, R. V. Skoryunov, O. A. Babanova, A. V. Skripov, J. J. Rush, A. Unemoto, H. Takamura, S. I. Orimo, Adv. Mater. 2014, 26, 7622.
[5] W. S. Tang, M. Matsuo, H. Wu, V. Stavila, W. Zhou, A. A. Talin, A. V Soloninin, R. V Skoryunov, O. A. Babanova, A. V Skripov, Adv. Energy Mater. 2016, 6, 1502237.
[6] J. ichi Aihara, J. Am. Chem. Soc. 1978, 100, 3339.
[7] R. J. Wiersema, M. F. Hawthorne, Inorg. Chem. 1973, 12, 785.
[8] M. Brighi, Oral Contribution at Swiss & Surrounding Battery days 2019, Dübendorf (Switzerland)
[9] L. Duchêne, R. S. Kühnel, E. Stilp, E. Cuervo Reyes, A. Remhof, H. Hagemann, C. Battaglia, Energy Environ. Sci. 2017, 10, 2609.
[10] F. Murgia, M. Brighi, R. Černý, Electrochem. commun. 2019, 106, 106534.
[11] M. Brighi, F. Murgia, R. Černý, Cell Report Physical Science 2020, 1, 100217