Sánchez-Diez Eduardo, Garcia Lorena, Arcelus Oier, Qiao Lixin, San Felices Leire, Carrasco Javier, Armand Michel, Martínez-Ibañez Maria, Zhang Heng
Centre for Cooperative Research on Alternative Energies (CIC EnergiGUNE), Basque Research and Technology Alliance (BRTA), Vitoria-Gasteiz, Spain.
Servicios Generales de Investigación SGIker, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Bilbao, Spain.
Front Chem. 2023 Jul 12;11:1191394. doi: 10.3389/fchem.2023.1191394. eCollection 2023.
Sulfonimide salts are of great interest for battery use thanks to their special properties including sufficient superior chemical/thermal stabilities, structural flexibility, In particular, the hydrogen-containing sulfonimide (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide anion {[N(SOCFH) (SOCF)], DFTFSI}, stands out owing to its suppressed anion mobility and superior electrochemical properties. We herein report the structural analyses of potassium (difluoromethanesulfonyl)(trifluoromethanesulfonyl)imide {K [N(SOCFH) (SOCF)], KDFTFSI} by virtue of single crystal X-ray diffraction and computational approaches. Our results reveal that KDFTFSI crystallizes in a orthorhombic cell (space group: Pbcn) comprising of cationic and anionic layers, which is similar to the conventional sulfonimide salt, potassium bis(trifluoromethanesulfonyl)imide {K [N(SOCF)], KTFSI}. Gas-phase density functional theory calculations show that the conversion from to DFTFSI anions is hindered due to the presence of stabilizing intramolecular H-bonding interactions in the conformer; yet interaction with K substantially minimizes the energy difference between the two conformers due to the formation of strong tridentate K coordination with oxygen atoms in the KDFTFSI. This work is anticipated to provide further understanding on the structure-property relations of hydrogenated sulfonimide anions, and thus inspire the structural design of new anions for battery research.
由于其特殊性质，包括足够优异的化学/热稳定性、结构灵活性，磺酰亚胺盐在电池应用中备受关注。特别是，含氢磺酰亚胺（二氟甲磺酰基）（三氟甲磺酰基）亚胺阴离子{[N(SOCFH)(SOCF)]，DFTFSI}因其抑制的阴离子迁移率和优异的电化学性能而脱颖而出。我们在此通过单晶X射线衍射和计算方法报告了（二氟甲磺酰基）（三氟甲磺酰基）亚胺钾{K[N(SOCFH)(SOCF)]，KDFTFSI}的结构分析。我们的结果表明，KDFTFSI结晶在一个正交晶胞（空间群：Pbcn）中，由阳离子层和阴离子层组成，这与传统的磺酰亚胺盐双（三氟甲磺酰基）亚胺钾{K[N(SOCF)]，KTFSI}相似。气相密度泛函理论计算表明，由于在 conformer 中存在稳定的分子内氢键相互作用，从 到 DFTFSI 阴离子的转化受到阻碍；然而，由于在 KDFTFSI 中与氧原子形成强三齿 K 配位，与 K 的相互作用极大地减小了两种构象异构体之间的能量差。这项工作有望进一步理解氢化磺酰亚胺阴离子的结构-性质关系，从而激发用于电池研究的新型阴离子的结构设计。
