Stable and highly LiCl concentrated electrolyte with In-situ synthesis of anion receptor

Abstract A concentrated lithium salt solution is widely used as an electrolyte of lithium-ion batteries. We have previously reported that simple and flexible ditopic receptors bearing anion and cation recognition sites forms LiCl complex resulting in the highly concentrated solution in acetonitrile. In this study, we conducted a novel in-situ synthesis by mixing receptor precursors, LiCl, and solvent. We found that the concentration of the receptor•LiCl complex increased from 0.25 M to 3 M, twelve times higher than the conventional simple mixing in acetonitrile. The ionic conductivity of the 3 M solution was successfully measured to be 1.41 × 10 −2 mS cm −1 at 25 °C. We elucidated that the in-situ electrolyte preparation enables us to obtain homogeneous and stable solutions even with high LiCl concentration. Moreover, the oxidation decomposition potential was 6 V vs. Li/Li + . This study presents a novel method for the preparation of highly concentrated electrolytes. We could obtain the electrolyte by one-pot synthesis and mixing, which means that in-situ preparation can have a cost-effective advantage.