A VO2 based hybrid super-capacitor utilizing a highly concentrated aqueous electrolyte for increased potential window and capacity
Journal article, 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.

Highly concentrated electrolyte

NaTFSI

Supercapacitor

Stability

VO2

Author

Simon Lindberg

Chalmers, Physics, Materials Physics

Ndeye Maty Ndiaye

University of Pretoria

Ncholu Manyala

University of Pretoria

Patrik Johansson

Chalmers, Physics, Materials Physics

Aleksandar Matic

Chalmers, Physics, Materials Physics

Electrochimica Acta

0013-4686 (ISSN)

Vol. 345 136225

Subject Categories

Physical Sciences

Other Physics Topics

Chemical Sciences

DOI

10.1016/j.electacta.2020.136225

More information

Latest update

4/6/2022 9