Modifications of MXene layers for supercapacitors

By Yachao Zhu, K. Rajouâ, S. L. Vot, O. Fontaine, P. Simon, F. Favier. Nano Energy, 2020

239 citations recorded by the source corpus.

Abstract The re-stacking of Ti3C2Tx-MXene layers has been prevented by using two different approaches: a facile hard templating method and a pore-forming approach. The expanded MXene obtained by using MgO nanoparticles as hard templates displayed an open morphology based on crumpled layers. The corresponding electrode material delivered 180 F g−1 of capacitance at 1 A g−1 and maintained 99% of its initial capacitance at 5 A g−1 over five thousand charge-discharge cycles. On the other hand, the MXene foam prepared after heating a MXene-urea composite at 550°C, showed numerous macropores on the surface layer and a complex open 3D inner-architecture. Thanks to this foamy porous structure, the binder-free electrode based on the resulting MXene foam displayed a great capacitance of 203 F g−1 at 5 A g−1 current density, 99% of which was retained after five thousand cycles. In comparison, the pristine MXene –based electrode delivered 82 F g−1, only, in the same operating conditions. An asymmetric device built on a negative MXene foam electrode and a positive MnO2 electrode exhibited an attractive energy density of 16.5 Wh kg−1 (or 10 Wh L−1) and 160 W kg−1 (or 8.5 kW L−1) power density. Altogether, the enhanced performances of these nano-engineered 2D materials are a clear demonstration of the efficiency of the chosen synthetic approaches to work out the re-stacking issue of MXene layers.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/cdc4cf183ecc2148f5abc0a28b9bb4750797e1a6