Thermotropic ionic liquid crystals as lithium battery electrolytes

Novel organic electrolyte platforms are being investigated for use in next-generation lithium-ion batteries. A major target is the reduction of use of volatile organic solvents, towards less flammable electrolytes and safer electrochemical energy storage systems without sacrificing energy density. Here we report on a family of ionic liquid and thermotropic ionic liquid crystalline electrolytes with the general chemical structure alkyl-ALi, where "A" is a monovalent anion with differing chemistry. It is found that the thermal, structural, and ion transport properties of these solvent-free electrolytes is a strong function of both the alkyl chain length and the chemical nature of the bound anion. For certain compositions, the materials are found to have liquid crystalline behavior over a wide temperature range. These surfactant-like salts may be diluted with common electrolyte solvents to create super concentrated electrolytes with enhanced ionic conductivity compared with the solvent-free electrolyte and enhanced electrochemical stability compared with conventional electrolytes based on the same solvents.