The invention relates to an electrolyte for a metal air battery, and in particular, to an ionic liquid electrolyte for a metal air battery. The ionic liquid electrolyte includes an additive to improve oxygen solubility thereof. The invention also define a method of impregnating a fluorinated carbon compound into an electrode comprising depositing onto the electrode a dispersion comprising the fluorinated carbon compound dissolved in an organic solvent and placing the electrode in an inert environment.