Electrostatic self-assembly of 2D delaminated MXene (Ti3C2) onto Ni foam with superior electrochemical performance for supercapacitor

By Jing Guo, Yingyuan Zhao, Anmin Liu, T. Ma. Electrochimica Acta, 2019

158 citations recorded by the source corpus.

Abstract The existence of the oxygen-containing functional groups on MXene surface makes it a potential electrode material in supercapacitor based on a redox mechanism. However, the irreversible stacking of MXenes will lead to an insufficient utilization of these functional groups. To solve this problem, we fabricated a composite electrode comprised of 2D delaminated Ti3C2 sheets (d-Ti3C2) and 3D Ni foam (NF) by electrostatic self-assembly. In this electrode, d-Ti3C2 nanosheets are adsorbed on the surface of 3D Ni foam skeleton structure, eliminating the need for insulative polymer binders. The self-assembly strategy endows d-Ti3C2/NF composites with unique 2D/3D structure which possesses the merits of excellent conductivity, sufficient active sites, high charge transfer efficiency and short ions diffusion path. As a result, the d-Ti3C2/NF composite electrode exhibits a high specific capacitance up to 654 F g−1 at 1 A g−1 and good cycling stability. An asymmetrical supercapacitor with d-Ti3C2/NF composite as a positive electrode, bulk Ti3C2 (b-Ti3C2) as a negative electrode and 6 M KOH as electrolyte, exhibits a maximum energy density of 18.1 Wh kg−1 (at 397.8 W kg−1) and excellent cycling stability (80.6% after 5000 cycles). The results indicate that d-Ti3C2/NF composite is a promising electrode material for practical energy storage devices.

Subfields: Biomedical Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

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