Analysis of Dynamics of Sodium Electrolyte with Aluminum Additives with Nuclear Magnetic Resonance Spectroscopy

As part of the development of beyond-lithium batteries, research on sodium electrolyte chemistries have shown many promising systems. Though more challenging, there is also great interest in developing electrolytes for aluminum-based batteries. Mixed Na/Al-catenated ionic liquid electrolytes were developed utilizing an atomically disordered form of sodium chloride salt, denoted as δ-NaCl, of various concentrations which was mixed with 1-ethyl-3-methylimidazolium chloride and aluminum chloride (EmImCl/AlCl₃)_1.5)/(δ-NaCl)_x. Pulsed-field-gradient nuclear magnetic resonance spectroscopy was utilized to determine transport mechanics of ions at various concentrations. The results reveal improved aluminum transport mobility with higher sodium salt concentration despite increased viscosity, indicating significant changes in the Al coordination shell with increasing δ-NaCl concentration.