Synthesis of Molecular Crystals with Ion-Conductive Paths for Selective Lithium Ion Diffusion

Abstract

Molecular crystals (MCs) consisting of an ordered arrangement of supramolecules are attractive compounds to develop novel materials because of the structural versatility of component units and their hierarchical structures. Lithium ion conductivity is one of the most important functions of such MCs because of their potential applications as solid electrolytes for next-generation batteries. Although it is known that the ionic conduction path is one of the most attractive key structures to generate solid-state ion diffusivity, lithium ion conducting MCs show limited ion conductivity that is not sufficient for practical applications at present. The authors investigated the systematic structural control of the ionic conduction paths in MCs through the modification of the component molecules. In this review, the structure-conductivity relationships of the molecular crystalline electrolytes synthesized by the authors are described, together with a guideline to develop molecular-based solid electrolytes exhibiting fast and selective lithium ion conduction.