MXenes as an emerging class of two-dimensional materials for advanced energy storage devices

Abstract

A class of two-dimensional (2D) transition metal nitrides and carbides (MXenes) has emerged as a promising paradigm. Their unique architecture such as controllable interfacial chemistry, high electronic conductivity, tunable layered...

Construction and Ion Transport-Related Applications of the Hydrogel-Based Membrane with 3D Nanochannels

“…Solid electrolytes have relatively high internal resistance [ 124 ]. Hydrogels are regarded as high-potential electrolyte materials transporting ions and as separators between the poles [ 125 ]. The main parameters to measure the performance of electrolytes are ionic conductivity—to achieve efficient ion transport; mechanical strength—good mechanical properties; and flexibility—repeated deformation ability.…”

Hierarchical MXene/transition metal oxide heterostructures for rechargeable batteries, capacitors, and capacitive deionization

“…[44][45][46][47] Since the discovery of Ti 3 C 2 T x in 2011, various MXenes (e.g., Ti 3 C 2 , Nb 4 C 3 , Nb 2 C, Ti 2 C, V 2 C, and Mo 1.33 C) with excellent physical and chemical properties have been prepared and utilized as electrode materials for rechargeable batteries, capacitors, and CDI. [48][49][50][51][52][53][54][55][56] In addition, owing to the existence of the large termination groups, MXene sheets can also be used as carriers to load other functional materials. Nevertheless, MXene electrodes suffer from the following issues: (1) low capacity or capacitance; (2) MXene sheets can be easily restacked during the preparation of the electrodes; (3) the electronic conductivity of MXene sheets decreases with the oxidation of the MXene; and (4) termination -F groups may influence the electrolyte infiltration into the electrodes.…”

Facet engineering of ultrathin two-dimensional materials

“…The former has strong in-plane chemical bonds and weak out-of-plane van der Waals bonds; while the latter has strong chemical bonds in threedimensional (3D) directions. 32 Due to the atomic thickness, large specific surface area, and quantum-confined effect, ultrathin 2D materials exhibit many excellent properties, such as high catalytic activity, 33,34 high mobility, 3,35 quantum Hall effect, 36 superconductivity, 37 etc., making them hot candidates in energy, 38,39 optoelectronics, 13,40 magnetism, 41 quantum communication, 42 and other applications. 43 It is noticed that when the dimension of the material is reduced to two dimensions, it exhibits plentiful and excellent properties and is widely used in various fields.…”

“…32 Due to the atomic thickness, large specific surface area, and quantum-confined effect, ultrathin 2D materials exhibit many excellent properties, such as high catalytic activity, 33,34 high mobility, 3,35 quantum Hall effect, 36 superconductivity, 37 etc. , making them hot candidates in energy, 38,39 optoelectronics, 13,40 magnetism, 41 quantum communication, 42 and other applications. 43…”