Uh, what practical capacitors for the last 90+ years have not been electrochemical in nature (the paper-in-oil capacitor has been around since the 1920s)? I swear, these ScienceDaily writers prove themselves the dumbest bunch of apes on the planet, again and again. Does your garden variety cap contain an electrolyte? Well, there you go!
The point here isn't the electolyte. It's the electrodes, which is what actually stores and releases the charge(s).