• carbon;
  • electrochemistry;
  • energy storage;
  • pseudocapacitance;
  • supercapacitor
Thumbnail image of graphical abstract

The cover image highlights research by the group of Elzbieta Frackowiak at Poznan University of Technology, who describe in a Communication on p. 1181 the advantages of aqueous solutions of conjugated redox couples applied as electrolytes for electrochemical capacitors. Solutions of potassium iodide and vanadyl sulphate are investigated, and allow to reach high capacitance and voltage values. The energy density is about 20 Wh kg−1 with a maximum power density of 2 kW kg−1. These electrolytes offer an interesting alternative to organic electrolytes, which are usually applied in commercial supercapacitors.