Abstract
Boronium ions are one of the most promising, yet most under-studied, types of cations of potential utility in ionic liquids and their electrochemical applications. While most mono-boron compounds are highly sensitive to air and water, boronium ions tend to be robust to both, as well as being comparable in thermal stability to more classical organic electrolyte ions such as quaternary ammoniums and imidazoliums. Using boronium ions, we have recently created new IL electrolytes that are competitive (in terms of the width of their electrochemical window) with widely-used ILs such as N,N-dialkylpyrrolidiniums; Further, high-level ab initio calculations have now shed light into the origin of their stability, and provide insights into how modifications to their basic structures could lead to ions with every better performance.