A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte

Youbing Li , Hui Shao , Zifeng Lin , Jun Lu , Liyuan Liu , Benjamin Duployer , Per Persson , Per Eklund , Lars Hultman , Mian Li , Ke Chen , Xian-Hu Zha , Shiyu Du , Patrick Rozier , Zhifang Chai , Encarnación Raymundo-Piñero (1) , Pierre-Louis Taberna , Patrice Simon , Qing Huang

1 CEMHTI - Conditions Extrêmes et Matériaux : Haute Température et Irradiation

Two-dimensional carbides and nitrides of transition metals, known as MXenes, are a fast-growing family of materials that have attracted attention as energy storage materials. MXenes are mainly prepared from Al-containing MAX phases (where A = Al) by Al dissolution in F-containing solution; most other MAX phases have not been explored. Here a redox-controlled A-site etching of MAX phases in Lewis acidic melts is proposed and validated by the synthesis of various MXenes from unconventional MAX-phase precursors with A elements Si, Zn and Ga. A negative electrode of Ti3C2 MXene material obtained through this molten salt synthesis method delivers a Li+ storage capacity of up to 738 C g−1 (205 mAh g−1) with high charge–discharge rate and a pseudocapacitive-like electrochemical signature in 1 M LiPF6 carbonate-based electrolyte. MXenes prepared via this molten salt synthesis route may prove suitable for use as high-rate negative-electrode materials for electrochemical energy storage applications.

Mots clés: MXenes; Lewis acidic melts; Energy storage materials; Electrochemical energy storage applications

Domaines: Matériaux; Matériaux; Energie électrique

Youbing Li, Hui Shao, Zifeng Lin, Jun Lu, Liyuan Liu, et al.. A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte. Nature Materials, 2020, 19 (8), pp.894-899. ⟨10.1038/s41563-020-0657-0⟩. ⟨hal-03065962v2⟩