Efficient electrode material for electrochemical energy storage from organic waste

Journal of Solid State Electrochemistry - Heteroatom functionalities in activated carbons have a positive effect on their electrochemical properties. High surface area, reasonable heteroatom...     

Fluoride based electrode materials for advanced energy storage devices

Energy storage and conversion have become a prime area of research to address both the societal concerns regarding the environment and pragmatic applications such as the powering of an ever increasing cadre of portable electronic devices. This paper reviews the use of fluoride based electrode materials in energy storage devices. The majority of the energy storage and conversion applications for fluorine based materials resides in present and future lithium battery chemistries. The use of fluorides either as coatings or in the formation of oxyfluorides has resulted in a marked increase of the stability and morphological development of electrodes for use in nonaqueous lithium and lithium-ion batteries. Pure fluorides, despite their intrinsic insulative properties, have demonstrated the capability to exhibit exceptional energy densities and have the potential to open the door to future high energy lithium battery technology.     

Mechanochemical synthesis and electrochemical properties of nanostructured electrode materials for Li ion batteries

We focus on the synthesis by ball milling and on the electrochemical characterization of nanocrystalline bimetallic and composite materials to be employed as anodes in Li ion batteries. Ni₃Sn₄ and Ni₃Sn₂ based compounds were obtained by ball milling of three different Ni–Sn mixtures. The properties of the resulting anodes for Li ion batteries were evaluated as a function of composition. Moreover, a biphasic system is presented, with CoSn₂ and CoSn type structures, arising from the synthesis of the Sn₃₁Co₂₈C₄₁ composition. When cycled in a Li cell, this material showed a high reversible specific capacity, about 450 mA h g⁻¹, and a very good electrochemical and structural stability, making it of interest for application purposes. Contribution to the Fall Meeting of the European Materials Research Society, Symposium D: 9th International Symposium on Electrochemical–Chemical Reactivity of Metastable Materials, Warsaw, 17th–21st September, 2007.     

Nanostructured energy materials for electrochemical energy conversion and storage: A review

Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium–sulfur batteries, lithium–oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal–air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density,and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device.     

A controllable preparation of two-dimensional cobalt oxalate-based nanostructured sheets for electrochemical energy storage

Well-defined two-dimensional （2D） cobalt oxalate （CoC₂O₄·2H₂O） nanosheets exhibit more excellent property than common bulk cobalt oxalate due to high specific surface areas and high-efficient transport of ion and electron. However, the delicate control of the 2D morphology of CoC₂O₄·2H₂O during their synthesis remains challenging. Herein, 2D CoC₂O₄·2H₂O nanosheets （M1）, grown by straightforward che...     

Nano-graphite functionalized mesocellular carbon foam with enhanced intra-penetrating electrical percolation networks for high performance electrochemical energy storage electrode materials

Mesocellular carbon foam (MSU-F-C) is functionalized with hollow nanographite by a simple solution-phase method to enhance the intrapenetrating electrical percolation network. The electrical conductivity of the resulting material, denoted as MSU-F-C-G, is increased by a factor of 20.5 compared with the pristine MSU-F-C. Hollow graphite nanoparticles are well-dispersed in mesocellular carbon foam, as confirmed by transmission electron microscopy (TEM), and the d spacing of the (002) planes is 0.343 nm, which is only slightly larger than that of pure graphite (0.335 nm), suggesting a random combination of graphitic and turbostratic stacking. After nanographitic functionalization, the BET surface area and total pore volume decreased from 928 m(2) g(-1) and 1.5 cm(3) g(-1) to 394 m(2) g(-1) and 0.7 cm(3) g(-1), respectively. Thermogravimetric analysis in air shows that the thermal stability of MSU-F-C-G is improved relative to that of MSU-F-C, and the one-step weight loss indicates that the nanographite is homogeneously functionalized on the MSU-F-C particles. When the resulting mesocellular carbon materials are used as electrode materials for an electric double layer capacitor (EDLC), the specific capacitances (C(sp)) of the MSU-F-C and MSU-F-C-G electrodes at 4 mV s(-1) are 109 F g(-1) and 93 F g(-1), respectively. The MSU-F-C-G electrode exhibited a very high area capacitance (C(area), 23.5 μF cm(-2)) compared with that of the MSU-F-C electrode (11.7 μF cm(-2)), which is attributed to the enhanced intraparticle conductivity by the nanographitic functionalization. MSU-F-C-G exhibited high capacity retention (52%) at a very high scan rate of 512 mV s(-1), while only a 23% capacity retention at 512 mV s(-1) was observed in the case of the MSU-F-C electrode. When applied as an anode in a lithium ion battery, a significant increase in the initial efficiency (44%), high reversible discharge capacity (580 mA h g(-1)) in the lower voltage region, and a higher rate capability were observed. The high rate capability of the MSU-F-C-G electrode as charge storage was due to the low resistance derived from the nanographitic functionalization.     

Unusual metals as electrode materials for electrochemical sensors

Although noble metals are still widely used in electroanalysis, a plethora of different nonconventional metals is now enriching the panorama of materials acting as the electrochemical transducer in sensing systems. In particular, Ti, Cu, Co, Fe, Mo, Ta, W, Rh, Bi, Sb, Te and Pb are discussed here in view of their peculiar physicochemical properties and of the interesting electrocatalytic activities ascribable to these elements and to the relevant metal oxide ultrathin films that spontaneously form at the electrode–solution interface. This behaviour, exploitable in electroanalysis for the detection of a number on analytes, is often accompanied by low price and high resistance to corrosion and to abrasion characterising these materials. These peculiarities encourage the possible use of the cited metals in a wide number of analytical frames, ranging from process control to bioimplantable sensing systems.     

A review of electrode materials for electrochemical supercapacitors

In this critical review, metal oxides-based materials for electrochemical supercapacitor (ES) electrodes are reviewed in detail together with a brief review of carbon materials and conducting polymers. Their advantages, disadvantages, and performance in ES electrodes are discussed through extensive analysis of the literature, and new trends in material development are also reviewed. Two important future research directions are indicated and summarized, based on results published in the literature: the development of composite and nanostructured ES materials to overcome the major challenge posed by the low energy density of ES (476 references).     

Redox-active conjugated microporous polymers as electron-accepting organic pseudocapacitor electrode materials for flexible energy storage

Science China Chemistry - Efficient energy storage devices, i.e. pseudocapacitors, are being intensively pursued to address the environmental and energy crises. Most high-performance...     

Nanosized zinc oxides-based materials for electrochemical energy storage and conversion: Batteries and supercapacitors

Transition metal oxides(TMO) bring a novel direction for the development of energy store materials due to their excellent stability. They not only have high capacity and good cycle performance, but also are cheap and easily available. Zinc oxide(Zn O) as an important part of TMO have gradually attracted attention in the research of electrochemistry. Zn O, as a metal semiconductor with the advantages of wide band gap, possesses high ion migration rate, good chemical stability, simple preparation ...     

High-performance nanostructured bio-based carbon electrodes for energy storage applications

Cellulose - Polyacrylonitrile (PAN)-based carbon precursor is a well-established and researched material for electrodes in energy storage applications due to its good physical properties and...     

Functionalized graphene foam as electrode for improved electrochemical storage

We report on a non-covalent functionalization of graphene foam (GF) synthesized via chemical vapour deposition (CVD). The GF was treated with pyrene carboxylic acid (PCA) which acted as a source of oxygen and/or hydroxyl groups attached to the surface of the graphene foam for its electrochemical performance improvement. The modified graphene surface enabled a high pseudocapacitive effect on the GF. A specific capacitance of 133.3 F g^?1, power density ～ 145.3 kW kg^?1 and energy density ～ 4.7 W h kg^?1 were achieved based on the functionalized foam in 6 M KOH aqueous electrolyte. The results suggest that non-covalent functionalization might be an effective approach to overcome the restacking problem associated with graphene electrodes and also signify the importance of surface functionalities in graphene-based electrode materials.     

Rapid prototyping of electrochemical energy storage devices based on two dimensional materials

Rapid prototyping methods such as additive manufacturing (three dimensional printing) and laser scribing have attracted much attention for manufacturing next-generation electrochemical energy storage devices because of their simplicity, low cost, medium throughput, and ability to prepare electrodes with unique form factors and multiple functionalities, such as stretchability, flexibility, and wearability. Of the wide array of potential active materials that can be used for energy storage, two dimensional materials such as graphene, MXenes, and MoS₂ have exceptionally high conductive surface areas and are attractive candidates for printing thick, high loading supercapacitors and batteries. In this brief review, we highlight recent progress and major challenges which must be overcome to make these manufacturing approaches and the resulting printed devices commercially viable.     

Emerging CoMn-LDH@MnO2 electrode materials assembled using nanosheets for flexible and foldable energy storage devices

CoMn layered double hydroxides(CoMn-LDH)are promising electrode materials for supercapacitors because of their excellent cyclic stability.However,they possess relatively low capacitances.In this work,hybrid CoMn-LDH@MnO2 products grown on Ni foams were obtained through a facile hydrothermal method.The as-synthesized samples employed as electrodes deliver a specific capacitance of 2325.01 F g^-1 at 1 A g^-1.An assembled asymmetric supercapacitor using these products as positive electrodes shows a maximum energy density of 59.73 W h kg^-1 at 1000.09 W kg^-1.The prominent electrochemical performance of the as-prepared electrodes could be attributes to hierarchical structures.These findings suggest that hybrid structures might be potential alternatives for future flexible energy storage devices.     

Flexible CuCo2O4@Ni-Co-S hybrids as electrode materials for high-performance energy storage devices

Rational design of electrode meterials with unique core-shell nanostructures is of great significance for improving the electrochemical performance of supercapacitors. In this work, we prepare several CuCo₂O₄ @Ni-Co-S composite electrodes by a controllable hydrothermal and electrodeposition route. One-dimensional nanowires can shorten the ions transport path, while two-dimensional nanosheets expose many active sites. This enables three-dimensional structured composite with high electrochemical activity. The as-prepared heterostructured materials show a specific of 1048 C/g at 1 A/g. It still maintains 75.6% of initial capacity after 20000 cycles at 10 A/g. The device delivers an energy density of 79.2 Wh/kg when the power density reaches to 2280 W/kg. Moreover, it possesses an excellent mechanical stability after repeated folding at different angles     

Single-atom catalysts for electrochemical energy storage and conversion

The expedited consumption of fossil fuels has triggered broad interest in the fabrication of novel catalysts for electrochemical energy storage and conversion.E...     

Polycationic oxides as potential electrode materials for aqueous-based electrochemical capacitors

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Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe₂O₃) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt₄BF₄ (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes.