Ionothermal synthesis and electrochemical properties of a selenidostannate containing the mixed cations of Na+ and enH+.

In this report, by taking advantages of the competitive and synergistic effects of mixed-cations under the ionothermal conditions, a novel selenidostannate compound containing the mixed cations, namely (enH) 3 Na[Sn 3 Se 7 ] 2 ·1.5Me 2 NH·1.5H 2 O ( 1 , en=ethylenediamine, Me 2 NH=dimethylamine) was obtained in the presence of the ionic liquid (IL) [DAMS]I (4-N,N-Dimethylamino-4′-N′-methylstilbazolium iodide) with a bulky and more structurally rigid organic cation as the main solvent and en as the auxiliary solvent. The compound features anionic [ Sn 3 Se 7 ] n 2 n - layers that are interconnected by sodium ions to form a three-dimensional (3D) structure. The syntheses, structure, thermal, optical and electrochemical properties of 1 were investigated. 1 showed good thermal stability and a Na + ion storage property without capacity fading over 150 cycles. [ABSTRACT FROM AUTHOR]