Li Youbing, Shao Hui, Lin Zifeng, Lu Jun, Liu Liyuan, Duployer Benjamin, Persson Per O Å, Eklund Per, Hultman Lars, Li Mian, Chen Ke, Zha Xian-Hu, Du Shiyu, Rozier Patrick, Chai Zhifang, Raymundo-Piñero Encarnacion, Taberna Pierre-Louis, Simon Patrice, Huang Qing
Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China.
University of Chinese Academy of Sciences, Beijing, China.
Nat Mater. 2020 Aug;19(8):894-899. doi: 10.1038/s41563-020-0657-0. Epub 2020 Apr 13.
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 TiC MXene material obtained through this molten salt synthesis method delivers a Li storage capacity of up to 738 C g (205 mAh g) with high charge-discharge rate and a pseudocapacitive-like electrochemical signature in 1 M LiPF 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.
过渡金属的二维碳化物和氮化物，即MXenes，是一类快速发展的材料家族，作为储能材料已引起关注。MXenes主要通过在含氟溶液中溶解铝，由含铝的MAX相（其中A = Al）制备；大多数其他MAX相尚未被探索。本文提出了一种在路易斯酸性熔体中对MAX相进行氧化还原控制的A位蚀刻方法，并通过从具有A元素Si、Zn和Ga的非常规MAX相前驱体合成各种MXenes进行了验证。通过这种熔盐合成方法获得的TiC MXene材料负极，在1 M LiPF碳酸盐基电解质中，具有高达738 C g（205 mAh g）的锂存储容量、高充放电速率和类似赝电容的电化学特征。通过这种熔盐合成路线制备的MXenes可能被证明适用于作为电化学储能应用的高倍率负极材料。
