Supercapacitors of Nanocrystalline Metal–Organic Frameworks

Abstract

The high porosity of metal-organic frameworks (MOFs) has been used to achieve exceptional gas adsorptive properties but as yet remains largely unexplored for electrochemical energy storage devices. This study shows that MOFs made as nanocrystals (nMOFs) can be doped with graphene and successfully incorporated into devices to function as supercapacitors. A series of 23 different nMOFs with multiple organic functionalities and metal ions, differing pore sizes and shapes, discrete and infinite metal oxide backbones, large and small nanocrystals, and a variety of structure types have been prepared and examined. Several members of this series give high capacitance; in particular, a zirconium MOF exhibits exceptionally high capacitance. It has the stack and areal capacitance of 0.64 and 5.09 mF cm(-2), about 6 times that of the supercapacitors made from the benchmark commercial activated carbon materials and a performance that is preserved over at least 10000 charge/discharge cycles.

Encapsulation of curcumin in cyclodextrin-metal organic frameworks: Dissociation of loaded CD-MOFs enhances stability of curcumin

“…Among these edible MOFs, cyclodextrin-MOFs (CD-MOFs), as shown Fig. 1A, is produced by using c-cyclodextrin (c-CD) (Choi et al, 2014), a symmetrical cyclic oligosaccharide obtained from starch and composed of eight asymmetric a-1,4-linked Dglucopyranosyl moieties (Smaldone et al, 2010). The building units in CD-MOFs are connected by potassium ions in aqueous media at suitable temperature and pressure, producing a body-centred cubic structure (Smaldone et al, 2010).…”

Nitrogen‐Doped Carbon Membrane Derived from Polyimide as Free‐Standing Electrodes for Flexible Supercapacitors

“…[ 12 ] The electrode materials with high electrical conductivity and accessible surface area can achieve high electrical double layer (EDL) capacitances, which can further enhance the pseudocapacitance by loading transition metal oxides and/or electronically conducting polymers. [ 13,14 ] However, the excess micropores of electrodes decrease the volumetric capacity, and pseudocapacitive components suffer from the short cyclic stability and the low stability of devices. [15][16][17][18][19] Recently, thin fi lm and fi ber-shaped supercapacitors with high packing density electrodes have attracted great attentions for relatively high volumetric energy density and long lifetimes, based on rGO and/or CNT fi lms by fi ltration, CNT fi bers, rGO fi bers, carbon fi bers.…”

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

“…They have been widely used as templates and precursors to synthesis carbon [2] and metal oxide materials [3]. Recently MOFs have received huge attention for clean energy applications such as fuel cells [4], Li-ion batteries [5,6] and supercapacitors [7]. In the field of lithium ion batteries, many research works have emerged rapidly since Tarascon et al discovered the first cathode material MIL-53(Fe) with a gravimetric capacity of 75 mA h g À 1 [8].…”