The Progress and Roadmap of Metal-Organic Frameworks for High-Performance Supercapacitors

The progress and roadmap of metal–organic frameworks for high-performance supercapacitors

Electrochemical carbon dioxide reduction reaction (eCO2RR) to value-added chemicals is considered as a promising strategy for CO2 conversion with economic and environmental benefits. Recently, investigations in eCO2RR to produce chemicals as energy or chemical industrial feedstock have received much attention. The eCO2RR generally occurs at the interface between electrode/electrocatalyst and electrolyte including charge transfer, phase transformation and mass transport. One of key problems in the electrochemical reaction is mass transfer limitation owing to the gaseous property of CO2 with low concentration on the surface of electrode/electrocatalyst. Several strategies were employed to improve mass transfer in the past years, including electrochemical reactors, electrodes, electrocatalysts and electrolytes, etc. which could low reaction barriers so adequately that reaction rates can be realized that are sufficient for eCO2RR. This article comprehensively reviewed development related to mass transfer study of CO2, including the mechanism of mass transfer of CO2, and main factors (electrodes, electrocatalysts and electrolytes) on two-phase or multi-phase interface during eCO2RR. The article is not aim at providing a comprehensive review of technical achievements towards eCO2RR technology, but rather to highlight electrode, catalyst, electrolyte, and other factors, which can understand the above components or factors' effects towards mass transfer investigations, to decouple mass transfer limitations and improve the performance of electrochemical CO2 conversion. Furthermore, the challenges and perspectives for mass transfer to eCO2RR are proposed. 

Mass transfer effect to electrochemical reduction of CO2: Electrode, electrocatalyst and electrolyte

Metal-organic frameworks (MOFs) with diverse composition, tunable structure, and unique physicochemical properties have emerged as promising materials in various fields. The tunable pore structure, abundant active sites, and ultrahigh specific surface area can facilitate mass transport and provide outstanding capacity, making MOFs an ideal active material for electrochemical energy storage and conversion. However, the poor electrical conductivity of pristine MOFs severely limits their applications in electrochemistry. Developing conductive MOFs has proved to be an effective solution to this problem. This review focuses on the design and synthesis of conductive MOF composites with judiciously chosen conducting materials, pristine MOFs, and assembly methods, as well as the preparation of intrinsically conductive MOFs based on building 2D π-conjugated structures, introducing mixed-valence metal ions/redox-active ligands, designing π-π stacked pathways, and constructing infinite metal-sulfur chains (-M-S-)∞ . Furthermore, recent progress and challenges of conductive MOFs for energy storage and conversion (supercapacitors, Li-ion batteries, Li-S batteries, and electrochemical water splitting) are summarized.

Recent Progress of Advanced Conductive Metal-Organic Frameworks: Precise Synthesis, Electrochemical Energy Storage Applications, and Future Challenges.

Supercapacitor (SC) is generally regarded as a promising electrochemical device in the field of energy storage. Electrode materials, as one of the components of SCs, play an important role in the electrochemical performance of energy storage devices. Thus, it is essential to look for or synthesize new electrode materials. Metal-organic frameworks (MOFs) material, as a crucial classification of new materials in metal-organic materials (MOM) has been widely studied in SCs due to their multifunctional diversities, inherent porosity, large specific surface area, tunable pore size distribution, and simple synthesis method. In this review, we present recent research advances in developing various support materials (e.g., carbon nanotube, carbon nanofiber, and metal supports) to enhance the electrochemical performance of SCs. Specially, we provide a detailed overview of the latest research advances in MOF-derived materials and composites in SCs. At last, current developments are summarized and critical challenges for driving these intriguing developments toward practical applications are discussed together with promising solutions. 

Recent advances in metal-organic framework-based electrode materials for supercapacitors: A review

http://manuscript.elsevier.com/S0378775322001835/pdf/S0378775322001835.pdf

In situ anodic electrodeposition of two-dimensional conductive metal-organic framework@nickel foam for high-performance flexible supercapacitor

Uniform size of Si nanowires (NWs) is highly desirable to enhance the performance of Si NW-based lithium-ion batteries. To achieve a narrow size distribution of Si NWs, the formation of bulk-like Si structures such as islands and chunks needs to be inhibited during nucleation and growth of Si NWs. We developed a simple approach to control the nucleation of Si NWs via interfacial energy tuning between metal catalysts and substrates by introducing a conductive diffusion barrier. Owing to the high interfacial energy between Au and TiN, agglomeration of Au nanoparticle catalysts was restrained on a TiN layer which induced the formation of small Au nanoparticle catalysts on TiN-coated substrates. The resulting Au catalysts led to the nucleation and growth of Si NWs on the TiN layer with higher number density and direct integration of the Si NWs onto current collectors without the formation of bulk-like Si structures. The lithium-ion battery anodes based on Si NWs grown on TiN-coated current collectors showed improved specific gravimetric capacities (>30%) for various charging rates and enhanced capacity retention up to 500 cycles of charging–discharging.

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Sun Hae Ra Shin

Papers

In situ anodic electrodeposition of two-dimensional conductive metal-organic framework@nickel foam for high-performance flexible supercapacitor

A controlled nucleation and growth of Si nanowires by using a TiN diffusion barrier layer for lithium-ion batteries