Structural Interactions within Lithium Salt Solvates: Cyclic Carbonates and Esters

Abstract

Only limited information is available regarding the manner in which cyclic carbonate and ester solvents coordinate Li + cations in electrolyte solutions for lithium batteries. One approach to gleaning significant insight into these interactions is to examine crystalline solvate structures. To this end, eight new solvate structures are reported with ethylene carbonate, γ-butyrolactone, and γ-valerolactone: (EC) 3:LiClO 4, (EC) 2:LiClO 4, (EC) 2:LiBF 4, (GBL) 4:LiPF 6, (GBL) 1:LiClO 4, (GVL) 1:LiClO 4, (GBL) 1:LiBF 4, and (GBL) 1:LiCF 3 SO 3 . The crystal structure of (EC) 1:LiCF 3 SO 3 is also re-reported for comparison. These structures enable the factors that govern the manner in which the ions are coordinated and the ion/solvent packing—in the solid-state—to be scrutinized in detail.