Porous heterostructured MXene/carbon nanotube composite paper with high volumetric capacity for sodium-based energy storage devices. (August 2016)

• Record Type: Journal Article
• Authors: Xie, Xiuqiang; Zhao, Meng-Qiang; Anasori, Babak; Maleski, Kathleen; Ren, Chang E.; Li, Jingwen; Byles, Bryan W.; Pomerantseva, Ekaterina; Wang, Guoxiu; Gogotsi, Yury
• Is Part Of: Nano energy. Volume 26(2016:Aug.)
• Page Start: 513
• Page End: 523
• Publication Date: 2016-08
• Subjects: MXene -- Porous films -- Sodium manganite -- Na-ion capacitor -- Volumetric capacity; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2016.06.005
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The global availability of sodium and a possibility to avoid the use of copper current collectors make electrochemical sodium-ion storage attractive for battery and metal-ion capacitor applications. However, the use of Na instead of Li ions requires different electrode materials that can accommodate larger Na ions and still provide high charging rate and high volumetric capacity. Herein we report on the fabrication of porous Ti3 C2 MXene/CNT composite paper electrodes for sodium-based energy storage devices. The heterostructure formation was realized by electrostatic attraction between negatively charged 2D MXene nanosheets and positively charged 1D CNTs. This method efficiently prevented restacking of MXene nanosheets and produced a well-defined porous structure, thereby facilitating electrolyte transport and access of ions to the electrode and producing functional MXene-based electrodes for sodium-ion storage. When applied as freestanding electrodes for sodium-ion storage, the built-to-order Ti3 C2 MXene/CNTs porous films showed high volumetric capacity of 421 mA h cm −3 at 20 mA g −1, good rate performances, and excellent cycling stability. Prototype sodium-ion cells were also assembled using the as-prepared Ti3 C2 /CNTs anode and Na0.44 MnO2 cathode. The fabrication of porous MXene/CNT composites, using simple self-assembly, opens the door to developing electrode materials with high volumetric capacity for sodium-ion storage. Graphical abstract: Porous MXene/CNT films were prepared by a self-assembly approach. When applied as a freestanding electrode for storage of sodium-ions, the porous MXene/CNT paper exhibited a high volumetric capacity, good rate performance, and excellent cycling stability. Highlights: Porous Ti3 C2 MXene/CNT composite films were prepared. The Ti3 C2 MXene/CNTs porous films showed superior performances for Na-ion storage. Prototype Na0.44 MnO2 //Ti3 C2 /CNTs Na-ion full cells were assembled. The general validity of the approach to prepare porous MXene/CNT was also demonstrated on Mo2 CTx .