A VO2 based hybrid super-capacitor utilizing a highly concentrated aqueous electrolyte for increased potential window and capacity
Artikel i vetenskaplig tidskrift, 2020

In this work we demonstrate the application of a highly concentrated aqueous electrolyte to a hybrid supercapacitor cell. We combine an 8 m Sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) aqueous electrolyte with a nanostructured VO2-cathode to enhance the voltage widow up to 2.4 V in a full cell. With the enhanced potential window, we are able to exploit the full contribution of the VO2 material, where a part is outside the stability window of standard alkaline aqueous electrolytes. We show that the VO2 material in the highly concentrated electrolyte provides a faradaic contribution even at the highest current density (25 A/g) and in this way increases the energy content also in high power conditions. The full cell shows a good efficiency but also a capacity fade over 500 cycles (39%) which is most likely related to dissolution of VO2.

Supercapacitor

Stability

NaTFSI

VO2

Highly concentrated electrolyte

Författare

Simon Lindberg

Chalmers, Fysik, Materialfysik

Ndeye Maty Ndiaye

Universiteit van Pretoria

Ncholu Manyala

Universiteit van Pretoria

Patrik Johansson

Chalmers, Fysik, Materialfysik

Aleksandar Matic

Chalmers, Fysik, Materialfysik

Electrochimica Acta

0013-4686 (ISSN)

Vol. 345 136225

Ämneskategorier

Fysik

Kemi

DOI

10.1016/j.electacta.2020.136225

Mer information

Senast uppdaterat

2020-08-28