(549g) Ternary Ionic Liquid Analogues for Rechargeable Metal Aluminum Batteries
- Conference: AIChE Annual Meeting
- Year: 2022
- Proceeding: 2022 Annual Meeting
- Group: Engineering Sciences and Fundamentals
- Time: Wednesday, November 16, 2022 - 5:15pm-5:30pm
Our recent research efforts focus on developing ILA electrolytes with varied anion-cation compositions to increase disorder, enhancing ionic conductivity and disrupting crystallization to improve performance under both ambient and low temperatures. Here, we study ternary electrolyte compositions of AlCl3-urea-EMIm[Cl] ILAs for use in rechargeable aluminum metal batteries, characterized by electrochemical, spectroscopic, and thermoanalytical measurements. The ILAs were synthesized such that the molar ratio of AlCl3 was kept constant in a ratio of 1.3:X:(1-X) where X is the mole fraction of urea in the binary urea-EMIm[Cl] composition space (0<X<1).
Quantitative liquid state 27Al and 1H nuclear magnetic resonance (NMR) spectroscopy was used to determine the ionic speciation of polyatomic aluminum complexes and understand how the local environments of the EMIm+ cations and urea changes with composition. Differential scanning calorimetry (DSC) was employed to understand the phase behavior of the electrolytes and determine their liquid-phase temperature windows. The ILA electrolytes were tested for their ability to reversibly electrodeposit aluminum metal, both galvanostatically (2-electrode symmetric cells) and potentiodynamically (3 electrode cells), including at low temperatures. Subsequently, the most promising electrolytes were tested in Al-graphite batteries to determine their technological feasibility and electrochemical properties, particularly at lower temperatures and fast charging/discharging rates. The overall results provide scientific insights into the design of AlCl3-urea-EMIm[Cl] ILA electrolytes for rechargeable aluminum metal batteries, for enhanced electrochemical performance, reduced cost, and expanded temperature window.
1. Zhang, Yu, et al 2018 Advanced Materials 30.38: 1706310.
2. Junfeng Li et al 2017 J. Electrochem. Soc. 164 A309