• batteries;
  • electrochemistry;
  • ionic liquids;
  • oxidation;
  • silicon
Thumbnail image of graphical abstract

The power of water: The cover picture illustrates the remarkable impact of the addition of water to ionic-liquid-based electrolyte on the discharge performance of Si–air batteries. The maximum cell discharge capacity is obtained with the addition of a few drops of water, where the cell capacity is substantially increased, compared to the cell capacity obtained with a pure ionic liquid electrolyte. This improvement is attributed to a shift in the reaction zone, leading to a formation of SiO2 in the bulk electrolyte, instead of solely being formed at the air electrode in a pure electrolyte. In a Full Paper by Cohn et al. on p. 1124, it is shown that water molecules play a major role in the battery discharge process of Si–air batteries, and thus, greatly affect the efficiency of the cell. This finding may have tremendous practical implications, because of the difficulty and cost of removing residual water from ionic liquids being used as battery electrolytes.