Polyfluorinated boron cluster – [B12F11H]2− – based electrolytes for supercapacitors: Overcharge protection

Redox-active polyfluorododecaborate cluster ions, [B12FxH12 − x]2−, were investigated as electrolytes for electrochemical double layer capacitors. In particular, the performance of tetraethylammonium undecafluorododecaborate, (Et4N)2B12F11H, was compared against a standard electrolyte made with tetraethylammonium tetrafluoroborate (Et4NBF4). Overcharge tests in single cells and in cells assembled in series demonstrated that the redox-active anion can be effectively used as a shuttle to reduce solvent degradation under harsh conditions, thus extending cell life.