Fluorination of MXene by Elemental F2 as Electrode Material for Lithium‐Ion Batteries. Issue 7 (21st March 2019)

• Record Type: Journal Article
• Authors: Thapaliya, Bishnu P.; Jafta, Charl J.; Lyu, Hailong; Xia, Jiexiang; Meyer, Harry M.; Paranthaman, M. Parans; Sun, Xiao‐Guang; Bridges, Craig A.; Dai, Sheng
• Is Part Of: ChemSusChem. Volume 12:Issue 7(2019)
• Page Start: 1316
• Page End: 1324
• Publication Date: 2019-03-21
• Subjects: batteries -- fluorination -- lithium-ion -- MXene -- TiOF2; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201900003
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: The transformation of MXene sheets into TiOF2 2D sheets with superior electrochemical performance was developed. MXene synthesized from Ti3 AlC2 was fluorinated for 3, 6, and 24 h, respectively, by means of a direct fluorination process. Exposure of MXene powder to elemental fluorine for 3 h induced the formation of CF2 groups and TiF3 on the surface, which have beneficial effects on the electrochemical performance. X‐ray photoelectron spectroscopy suggested that after fluorinating the MXene sample for 6 h Ti 2+ and Ti 3+ were not present on the surface but only Ti 4+, indicating the formation of TiOF2 . XRD indicated that TiOF2 was present after fluorinating for 3 h, and after 24 h the MXene had transformed to TiOF2 with minor impurities remaining, maintaining its 2D layer morphology. The 24 h fluorinated sample with its TiOF2 phase showed superior capacity that increased with cycle number. It also had a better rate capability than non‐2D‐layered TiOF2, indicating the advantage of the 2D‐layered morphology derived from the parent MXene phase. Abstract : 2D makes the difference : MXene fluorinated by means of a direct fluorination process for 24 h is transformed into TiOF2 sheets, maintaining the 2D layer morphology. This material exhibits superior electrochemical performance such as increased capacity, high rate capability, and long cycling stability for lithium‐ion batteries.