Hierarchical two‐dimensional Ti‐MOF derived from MXene for hybrid supercapacitor electrodes

Abstract

Presently, two‐dimensional (2D) metal–organic framework (MOF) are drawing increasing attention in energy‐storage areas. However, more and complexed factors would affect the nucleation and growth of 2D MOFs, and subsequently affect the final performance. Particularly, it is important to control the coordination rate between ions and ligands. In this paper, MXene was directly used as titanium source to coordinate with an organic ligand to form Ti‐MOF sheets. To further boost the performance, mesopores were introduced in preparing 2D Ti‐MOF, constructing hierarchical porous Ti‐MOF@Ti3C2TX hybrids. Results showed that diffusion‐controlled behaviors play a dominant role over surface capacitive behaviors during the charge storage process of the hierarchical porous hybrids. A hybrid supercapacitor (HSC) assembled with the obtained HP‐Ti‐MOF@Ti3C2TX and activated carbon (AC) exhibited an energy density of 22.9 Wh kg−1 at a power density of 850 W kg−1 (1 A g−1), and a power density of 4.25 kW kg−1 at an energy density of 15.3 Wh kg−1 (5 A g−1). The present strategy is expected to provide design ideas for novel energy‐storage electrode materials.