Design and Synthesis of Conductive Metal‐Organic Frameworks and Their Composites for Supercapacitors

Abstract

Supercapacitors possess important prospects in power supply, owing to the characteristics of fast charging/discharging and long cycling life. As emerging materials, metal-organic frameworks (MOFs) are the cutting-edge electrode active materials for supercapacitors due to their good conductivity, tunable pore structure, as well as diverse composition. In this Minireview, we summarize the recent progress in MOF electrodes for supercapacitors. We focus on the synthesis of intrinsically conductive MOFs constructed from different organic linkers and adjustable metal ions, and the preparation of conductive MOF composites hybridized with conducting materials (conducting polymers and carbons). Following the discussion of both different types of conductive MOFs and their composites in supercapacitors, the challenges, and opportunities of conductive MOF electrodes for supercapacitors are further prospected at the end of this contribution, which would provide some valuable insights in facilitating the use of MOF materials in energy-storage applications.

Self-supported metal–organic framework-based nanostructures as binder-free electrodes for supercapacitors

“…The good crystallinity, large surface area and excellent structural tunability make MOFs the best candidates for high-performance electrode materials. 21 However, the straightforward application of pristine MOFs is impeded by the relatively low electronic conductivity and poor stability during the electrochemical process. Alternatively, MOFs can be transformed into porous carbon, metal oxides/ hydroxides, metal sulfides, etc., wherein MOFs are utilized as templates/precursors.…”

Metal–Organic Frameworks and Their Derived Functional Materials for Supercapacitor Electrode Application

“…MOF composites are designed to mitigate the shortcomings or expand the advantages of pristine MOFs; thus, the materials usually display ideal electrical conductivity, good chemical stability, large specific surface areas, and acceptable mechanical properties, which can be selected as the main research objects to construct an electrode material with a better electrochemical performance. [ 50 ] In general, the electrochemical performance of MOF composites mainly depends on three aspects: 1) the architecture and metallic ions of MOFs. The former affects the diffusion and transport of electrolyte ions, and the valence variability of the latter is related to the pseudocapacitive activity.…”

Design of Oxygen‐doped Co3S4 Hollow Nanosheets by Suppressed Sulfurization for Supercapacitors

“…According to the energy storage mechanism, the use of pseudocapacitive materials involving transition metal sulfides, phosphides and hydroxides/oxides as positive electrodes can remarkably increase the energy density of supercapacitors [8–11] . Recently, metal‐organic frameworks (MOFs) with active metal centers also have been applied for the supercapacitors due to the tunable structures and large surface area [12,13] . However, these pseudocapacitive materials still suffer from the insufficient contact between the electrodes and electrolyte as well as sluggish ion/electron transport kinetics, which limits their further application [14] …”