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arXiv · 1909.13236

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

Abstract

Two-dimensional carbides and nitrides of transition metals, known as MXenes, are a fast-growing family of 2D materials that draw attention as energy storage materials. So far, MXenes are mainly prepared from Al-containing MAX phases (where A = Al) by Al dissolution in F-containing solution, but 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 up to 738 C g-1 (205 mAh g-1) with high-rate performance and pseudocapacitive-like electrochemical signature in 1M LiPF6 carbonate-based electrolyte. MXene prepared from this molten salt synthesis route offer opportunities as high-rate negative electrode material for electrochemical energy storage applications.

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Youbing Li, Hui Shao, Zifeng Lin, Jun Lu, Per O. A. Persson, Per Eklund, Lars Hultman, Mian Li, Ke Chen, Xian-Hu Zha, Shiyu Du, Patrick Rozier, Zhifang Chai, Encarnacion Raymundo-Piñero, Pierre-Louis Taberna, Patrice Simon, Qing Huang. 2019-09-29. A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte. https://arxiv.org/abs/1909.13236

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