Metal-organic Framework Electrode Research Articles

A nickel-based metal-organic framework: A novel optimized anode material for Li-ion batteries

A Ni-based metal-organic framework (MOF) was synthesized by a one-pot hydrothermal route and used as an anode material for lithium ion batteries (LIBs) for the first time. This Ni-based MOF has obvious ion diffusion channels which can be easily observed from its structural graph. As an anode material for LIBs, it delivers a reversible capacity of 620mAhg−1 at a current density of 100mAg−1 after 100 cycles. More importantly, it also shows excellent rate performance. Thus, this novel Ni-based MOF electrode will be a promising anode electrode for LIBs and further broaden the application field of MOFs materials.

Tunneling Electrical Connection to the Interior of Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) are typically poor electrical conductors, which limits their uses in sensors, fuel cells, batteries, and other applications that require electrically conductive, high surface area materials. Although metal nanoclusters (NCs) are often added to MOFs, the electrical properties of these hybrid materials have not yet been explored. Here, we show that adding NCs to a MOF not only imparts moderate electrical conductivity to an otherwise insulating material but also renders it photoconductive, with conductivity increasing by up to 4 orders of magnitude upon light irradiation. Because charge transport occurs via tunneling between spatially separated NCs that occupy a small percent of the MOF's volume, the pores remain largely open and accessible. While these phenomena are more pronounced in single-MOF crystals (here, Rb-CD-MOFs), they are also observed in films of smaller MOF crystallites (MIL-53). Additionally, we show that in the photoconductive MOFs, the effective diffusion coefficients of electrons can match the typical values of small molecules diffusing through MOFs; this property can open new vistas for the development of MOF electrodes and, in a wider context, of electroactive and light-harvesting MOFs.

Supercapacitive property of metal–organic-frameworks with different pore dimensions and morphology

Three dicarboxylic acids with different molecular lengths were used as organic linkers to manipulate pore size and surface area of the cobalt based metal–organic-frameworks (MOFs). The pore size and BET surface area of the MOFs were determined and the influence of pore size and surface area on the supercapacitive performance of the MOFs was studied using cyclic voltammetry and chronopotentiometry. Among three MOFs investigated in the present study, the MOF with longer organic linker had larger pores, larger surface area and the MOF film at the electrode surface had a continuously interconnected leaflet like microstructure with less number of structural interfaces which provide the free path for charge transfer. This MOF electrode exhibited highest supercapacitive properties with 179.2Fg−1, 31.4Whkg−1, and 5.64kWkg−1 of specific capacitance, energy density and power density, respectively.