Jankowski P, Wieczorek W, Johansson P
Faculty of Chemistry, Warsaw University of Technology, ul. Noakowskiego 3, 00-664 Warsaw, Poland.
Phys Chem Chem Phys. 2016 Jun 28;18(24):16274-80. doi: 10.1039/c6cp02409b. Epub 2016 Jun 2.
A new anion design concept, based on combining a boron atom as the central atom and conjugated systems as ligands, is presented as a route for finding alternative Li-salts for lithium-ion batteries. The properties of a wide range of novel anions designed in this way have been evaluated by DFT calculations focusing on three different fundamental success factors/measures: the strength of the cation-anion interaction, ultimately determining both the solubility and the ionic conductivity, the oxidation limit, determining their possible use vs. high voltage cathodes, and the reduction stability, revealing a possible role of the anion in the SEI-formation at the anode. For a few anions superior properties vs. today's existing or suggested anions are predicted, especially the very low cation-anion interaction strengths are promising features. The design route itself is shown to be versatile in determining the correlation between different choices of ligands and the resulting overall properties - where the most striking feature is the decreased lithium cation interaction energy upon using the (1Z,3Z)-buta-1,3-diene-1,2,3,4-tetracarbonitrile ligands. This also opens avenues for the further design of novel anions beyond those with a boron central atom.
提出了一种基于将硼原子作为中心原子和共轭体系作为配体相结合的新型阴离子设计概念，作为寻找锂离子电池替代锂盐的途径。通过密度泛函理论（DFT）计算，以三个不同的基本成功因素/指标为重点，评估了以这种方式设计的多种新型阴离子的性质：阳离子-阴离子相互作用的强度，最终决定溶解度和离子电导率；氧化极限，决定它们与高压阴极相比的可能用途；还原稳定性，揭示阴离子在阳极固体电解质界面（SEI）形成中的可能作用。预测了一些阴离子相对于当今现有或建议的阴离子具有优异的性能，特别是非常低的阳离子-阴离子相互作用强度是很有前景的特征。结果表明，该设计路线在确定配体的不同选择与所得整体性能之间的相关性方面具有通用性——其中最显著的特征是使用（1Z，3Z）-丁二烯-1,2,3,4-四腈配体时锂阳离子相互作用能降低。这也为进一步设计除含硼中心原子以外的新型阴离子开辟了道路。
