CAS: Collaborative Research: Boronium Ionic Liquids - Impact of Structure on Chemistry, Electrochemical Stability, Ion Dynamics, and Charge Transport

In this collaborative research, funded by the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division, James Davis of the Department of Chemistry at the University of South Alabama (USA) and Paul Trulove, Tyler Cosby, David P Durkin of the Chemistry Department of the U.S. Naval Academy (USNA) will prepare and characterize a new class of liquid salts (ionic liquids), that are unique in having boron-centered cations at their core.

The primary goal of this research is to investigate how the structure and composition of these boron-based ionic liquids impact key physical and chemical properties. This is vital information in that ionic liquids have the potential to serve as superior electrolytes (key battery components), and, as such, could lead to significant improvements in electrical energy storage (e.g., batteries, capacitors), synthetic electrochemistry, and the recovery of metals from electronic waste.

This project synergistically ties the synthesis efforts at USA with materials characterization at USNA in a dynamic cycle to drive optimized material performance. Furthermore, this collaborative effort at undergraduate-only research institutions provides the opportunity for significant involvement of undergraduate research scientists in cutting-edge science.

This project is expected to generate a library of structurally and compositionally novel ionic liquids based upon boronium cations paired with the triflimide anion [(CF3SO2)2N-]. The initial suite of compounds will consist of salts that include cyclic, bicyclic, and acylic boronium cations. These ionic liquids will then be characterized using a battery of physicochemical techniques which will interrogate their physical, spectroscopic, thermal, ionic, and electrochemical properties.

A major emphasis of this portion of the proposed work will be to elucidate the influence of specific cation molecular structure changes on the ion dynamics. The information gleaned from these studies will then, in combination with computational evaluations, be used in a feedback loop to guide the synthesis of new cation variants in order to (a) validate (or refute) the apparent relationships, and (b) guide the design of new cations with optimized properties, especially ones that may be germane to the use of these salts as electrolytes in energy devices (i.e., batteries, capacitors) and as dual solvent-electrolytes for synthetic electrochemistry and/or for the electrowinning of metals.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.