MS19-P01 Metal Hydro-Borates for Li- and Na-ion Batteries Radovan Černý (Laboratory of Crystallography, DQMP, University of Geneva, Geneva, Switzerland) Emilie Didelot (Laboratory of Crystallography, DQMP, University of Geneva, Geneva, Switzerland) Yolanda Sadikin (Laboratory of Crystallography, DQMP, University of Geneva, Geneva, Switzerland) Matteo Brighi (Laboratory of Crystallography, DQMP, University of Geneva, Geneva, Switzerland) Fabrizio Murgia (Laboratory of Crystallography, DQMP, University of Geneva, Geneva, Switzerland)email: Radovan.Cerny@unige.chComplex hydrides based on light hydro-borate anions such as borohydride BH4 or closo-borate anion B12H122− find their place as solid stores for hydrogen, and since recently, also as solid electrolytes in Li- and Na-ion batteries. The mobility of the cations depends on the pathways available in the anion packing, chemical interaction of cations with anions and on the anion thermal motion such as tumbling or rotation. While the latter two require important experimental and theoretical effort, the first parameter can be easily analysed and quantified from the crystal structure data obtained by X-ray diffraction. A thorough crystal chemistry analysis of observed crystal structures, allows us to find the structural aristotypes and to draw conclusions about the bonding and building principles in this important category of materials as it was done recently for the borohydrides (Figure 1).
Among others, the modification of Na2B12H12, promising Na-ion solid electrolyte, by anion modification and anion mixing will be shown. 1-2 Novel synthetic way completed by ab inito structural characterization using synchrotron X-ray powder diffraction and ab initio calculation allowed discovery of several 3d transition metal closo-borates - potentially battery electrodes (Figure 2).3
 
References:

[1] Sadikin Y., Schouwink P., Brighi M., Łodziana Z., Černý R, Inorg. Chem. 2017, 56, 5006-5016

[2] Brighi M., Murgia F., Łodziana Z., Schouwink P., Wolczyk A., Černý R., submitted to Adv. Energy Mater.

[3] Sadikin Y., Didelot E., Łodziana Z., Černý R., submitted to Dalton Trans.
Keywords: Na-ion battery, borate, transition metal