Flexible MXene‐Based Composite Films: Synthesis, Modification, and Applications as Electrodes of Supercapacitors

Abstract

MXenes, as a 2D planar structure nanomaterial, were first reported in 2011. Due to their large specific surface area, high ductility, high electrical conductivity, strong hydrophilic surface, and high mechanical flexibility, MXenes have been extensively explored in the development of various functional materials with desired performances. This review is aimed to summarize the current progress in synthesis, modification, and applications of MXene‐based composite films as electrode materials of flexible energy storage devices. In the synthesis of MXenes, the evolution and exploration of etchants are emphasized. Furthermore, in order to develop MXene‐based composite films, the components used to modify the MXene nanoflakes, including 0D, 1D, and 2D nanomaterials, are summarized, and the perspectives and research direction of such materials are also discussed.

3D Porous Structure in MXene/PANI Foam for a High‐Performance Flexible Pressure Sensor

“…Except for providing compressive space, the porous structure of processed material can greatly reduce the pressure resistance of materials and thus enhance the performance of devices. [17,18] As a member of the two-dimensional (2D) material family, MXenes hold lots of excellent properties, [19][20][21] such as large specific surface area and good conductivity, and have demonstrated promising application prospects in the fields of energy storage, [22][23][24] sensing, [25][26][27] catalysis, [28,29] electromagnetic shielding, [30][31][32] etc. MXenes are frequently employed as piezosensitive materials thanks to their exceptional physical and chemical properties.…”

“…As a member of the two‐dimensional (2D) material family, MXenes hold lots of excellent properties, [ 19–21 ] such as large specific surface area and good conductivity, and have demonstrated promising application prospects in the fields of energy storage, [ 22–24 ] sensing, [ 25–27 ] catalysis, [ 28,29 ] electromagnetic shielding, [ 30–32 ] etc. MXenes are frequently employed as piezosensitive materials thanks to their exceptional physical and chemical properties.…”

Few-layered Ti3C2TXcoupled with Fe3O4nanoparticles assembled in a reduced graphene oxide hydrogel as advanced electrodes for high-energy supercapacitors

“…However, the strong interlayer van der Waals interactions between adjacent Ti 3 C 2 T X nanosheets lead to a self-restacking phenomenon, which limits the utilization of the active surface area and the diffusion of ions, resulting in a poor performance. [28][29][30][31] To avoid self-stacking, one viable solution is to integrate the Fe 3 O 4 @Ti 3 C 2 T X heterostructures into a 3D interlinked framework which can not only impede self-restacking, but also produce abundant active sites and facile ion/electron transfer pathways to boost the electrochemical reaction kinetics. 25,32,33 In order to construct 3D porous architecture, the sol-gel method is more facile and low cost, compared to other methods.…”

In Situ Growth of Ni-MOF Nanorods Array on Ti3C2Tx Nanosheets for Supercapacitive Electrodes

“…M n+1 X n T x ( n = 1~4), in which M represents transition metals (e.g., Ti, V, etc. ), X is C or/and N, and T x stands for terminal groups, such as -O, -OH, and -F, on the surface [ 24 , 25 ], and also named MXene, has been developed quickly since it has excellent conductivity [ 26 , 27 ], many surface groups for functional modification [ 28 , 29 ], and other fascinating tunable properties [ 30 , 31 ]. Recently, Ti 3 C 2 T x , the most widely studied MXene, has been used in supercapacitors by diversiform-processing techniques [ 32 , 33 , 34 ].…”