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[Sn3Se7]2 center dot 1.5Me(2)NH center dot 1.5H(2)O (1, en=ethylenediamine, Me2NH=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 [Sn3Se7](n)(2n-) layers that are interconnected by sodium ions to form a three-dimensional (3D) structure. The syntheses, structure, thermal, optical and electrochemical properties of I were investigated. I showed good thermal stability and a Na+ ion storage property without capacity fading over 150 cycles. (C) 2016 Elsevier Inc. All rights reserved.