The physicochemical properties of aluminum trifluoromethanesulfonate in diglyme have been investigated. The spectroscopic and electrochemical properties have been examined to determine speciation, conductivity, and electrochemical stability. Gaussian calculations provide optimized molecular geometries and offer insight into the electrochemical behavior of the solutions. The ions in solution appear to exhibit very straightforward behavior, with contact ion pairs forming at very low concentrations. In addition, the electrochemical window of the electrolyte initially decreases with increasing salt concentration to a minimum value of approximately 5.5 V around 1 M and then steadily rises to a maximum value above 8 V.