Exfoliation and Delamination of Ti3C2Tx MXene Prepared via Molten Salt Etching Route

Liyuan Liu; Metin Orbay; Sha Luo; Sandrine Duluard; Hui Shao; Justine Harmel; Patrick Rozier; Pierre-Louis Taberna; Patrice Simon

doi:10.1021/acsnano.1c08498

Exfoliation and Delamination of Ti₃C₂T_x MXene Prepared via Molten Salt Etching Route

ACS Nano. 2022 Jan 25;16(1):111-118. doi: 10.1021/acsnano.1c08498. Epub 2021 Nov 17.

Authors

Liyuan Liu^{1

2}, Metin Orbay^{1

2}, Sha Luo^{1

3}, Sandrine Duluard¹, Hui Shao^{1

2}, Justine Harmel^{1

2}, Patrick Rozier^{1

2}, Pierre-Louis Taberna^{1

2}, Patrice Simon^{1

2}

Affiliations

¹ CIRIMAT, UMR CNRS 5085, Université Paul Sabatier Toulouse III, 118 Route de Narbonne, 31062 Toulouse, France.
² RS2E, Réseau Français sur le Stockage Electrochimique de l'Energie, FR CNRS 3459, 80039 Amiens Cedex, France.
³ State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, 730000 Lanzhou, Gansu, People's Republic of China.

PMID: 34787390
DOI: 10.1021/acsnano.1c08498

Abstract

MXenes are two-dimensional metal carbides or nitrides that are currently proposed in many applications thanks to their unique attributes including high conductivity and accessible surface. Recently, a synthetic route was proposed to prepare MXenes from the molten salt etching of precursors allowing for the preparation of MXene (denoted as MS-MXenes, for molten salt MXene) with tuned surface termination groups, resulting in improved electrochemical properties. However, further delamination of as-prepared multilayer MS-MXenes still remains a major challenge. Here, we report on the successful exfoliation of MS-Ti₃C₂T_x via the intercalation of the organic molecule TBAOH (tetrabutylammonium hydroxide), followed by sonication to separate the layers. The treatment time could be adapted to tune the wetting behavior of the MS-Ti₃C₂T_x. As a result, a self-supported Cl-terminated MXene film could be prepared by filtration. Finally, MS-Ti₃C₂T_x used as a Li-ion battery anode could achieve a high specific capacity of 225 mAh g^-1 at a 1C rate together with an excellent rate capability of 95 mAh g^-1 at 167C. These results also show that tuning of the surface chemistry of MXene is of key importance to this field with the likely result being increased electrochemical performance.

Keywords: Li-ion batteries; MXene; delamination; exfoliation; molten salt method.