Structural transformation of graphite by arc-discharge

The formation of novel structures by the passage of an electric current through graphite is described. These structures apparently consist of hollow three-dimensional graphitic shells bounded by curved and faceted planes, typically made up of two graphene layers. The curved structures were frequently decorated with nano-scale carbon particles, or short nanotubes. In some cases, nanotubes were found to be seamlessly connected to the thin shells, indicating that the formation of the shells and the nanotubes is intimately connected. Small nanotubes or nanoparticles were also sometimes found encapsulated inside the hollow structures, while fullerene-like particles were often seen attached to the outside surfaces. With their high surface areas and structural perfection, the new carbon structures may have applications as anodes of lithium ion batteries or as components of composite materials.

Electrostatic layer-by-layer deposition and electrochemical characterization of thin films composed of MnO(2) nanoparticles in a room-temperature ionic liquid

Thin films of MnO(2) nanoparticles were grown using the layer-by-layer method with poly (diallyldimetylammonium) as the intercalated layer. The film growth was followed by UV-vis, electrochemical quartz crystal microbalance (EQCM), and atomic force microscopy. Linear growth due to electrostatic immobilization of layers was observed up to 30 bilayers, but electrical connectivity was maintained only for 12 MnO(2)/PPDA bilayers. The electrochemical characterization of this film in 1-butyl-2,3-dimethyl-imidazolium (BMMI) bis(trifluoromethanesulfonyl)imide (TFSI) (BMMITFSI) with and without addition of a lithium salt indicated a higher electrochemical response of the nanostructured electrode in the lithium-containing electrolyte. On the basis of EQCM experiments, it was possible to confirm that the charge compensation process is achieved mainly by the TFSI anion at short times (<2 s) and by BMMI and lithium cations at longer times. The fact that large ions like TFSI and BMMI participate in the electroneutrality is attributed to the redox reaction that occurs at the superficial sites and to the high concentration of these species compared to that of lithium cations.

Avalia����o de catalisadores a base de carbeto e nitreto de molibd��nio na obten����o de lactitol via hidrogena����o da lactose

Seeking a greater appreciation of cheese whey was developed to process the hydrogenation of lactose for the production of lactitol, a polyol with high added value, using the catalyst Ni / activated carbon (15% and 20% nickel), the nitride Mo2N, the bimetallic carbide Ni-Mo/ activated carbon and carbide Mo2C. After synthesis, the prepared catalysts were analyzed by MEV, XRD, laser granulometry and B.E.T. The reactor used in catalytic hydrogenation of lactose was the type of bed mud with a pressure (68 atm), temperature (120 oC) and stirring speed (500 rpm) remained constant during the experiments. The system operated in batch mode for the solid and liquid and semi-continuous to gas. Besides the nature of the catalyst, we studied the influence of pH of reaction medium for Mo2C carbide as well as evaluating the character of the protein inhibitor and chloride ions on the activity of catalysts Ni (20%)/Activated Carbon and bimetallic carbide Ni-Mo/Activated Carbon. The decrease in protein levels was performed by coagulation with chitosan and adsorption of chloride ions was performed by ion exchange resins. In the process of protein adsorption and chloride ions, the maximum percentage extracted was about 74% and 79% respectively. The micrographs of the powders of Mo2C and Mo2N presented in the form of homogeneous clusters, whereas for the catalysts supported on activated carbon, microporous structure proved impregnated with small particles indicating the presence of metal. The results showed high conversion of lactose to lactitol 90% for the catalyst Ni (20%)/Activated Carbon at pH 6 and 46% for the carbide Mo2C pH 8 (after addition of NH4OH) using the commercial lactose. Monitoring the evolution of the constituents present in the reaction medium was made by liquid chromatography. A kinetic model of heterogeneous Langmuir Hinshelwood type was developed which showed that the estimated constants based catalysts promoted carbide and nitride with a certain speed the adsorption, desorption and production of lactitol

Effect of addition of MTES on the structure of siloxane-PPG nanocomposites

Hybrid transparent and flexible siloxane-polypropyleneglycol (PPG) materials with covalent bonds between the inorganic (siloxane) and organic (polymeric) phases were prepared by sol-gel process. In order to improve the quality of the mechanical properties of these materials, different amounts of methyltriethoxysilane (MTES) were added to the initial sol. The effect of MTES addition on the structure of the composites was studied by Small-Angle X-Ray Scattering (SAXS) and Si-29 Nuclear Magnetic Resonance (Si-29 NMR). In absence of MTES, SAXS spectra exhibit a peak that is assigned to spatial correlation due to short range order between the siloxane clusters embedded in the polymeric phase. The experimental results indicate that, for low MTES concentrations ([MTES]/[O] less than or equal to 0.8, O: ether-type oxygen of PPG), the silicon species resulting from hydrolysis and condensation of MTES fill the open spaces between polymeric chains, interacting with the ether-type oxygens. For larger MTES content ([MTES]/[O] greater than or equal to 0.8), the number of free ether-type oxygen sites avalaible for reaction with such silicon species is not large enough. Consequently, a fraction of silicon species resulting from MTES addition graft to siloxane clusters formed by hydrolysis and condensation of the hybrid precursor. For all MTES concentrations the condensation degree of the siloxane phase, determined from Si-29 NMR spectroscopy, is high (> 69%), as expected under neutral pH synthesis conditions.

Small-angle X-ray scattering and X-ray absorption near-edge structure study of iron-doped siloxane-polyoxyethylene nanocomposites

The local and medium-range structures of siloxane-POE hybrids doped with Fe(III) ions and prepared by the sol-gel process were investigated by X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) and small-angle X-ray scattering (SAXS), respectively. The experimental results show that the structure of these composites depends on the doping level. EXAFS data reveal that, for low doping levels ([O]/[Fe] > 40, oxygens being of the ether-type of the POE chains), Fe(III) ions are surrounded essentially by a shell of chlorine atoms, suggesting the formation of FeCl4- anions. At high doping levels ([O]/[Fe] < 20), Fe(III) ions interacts mainly with oxygen atoms and form FeOx species. The relative proportion of FeOx species increases with iron concentration, this result being consistent with the results of SAXS measurements showing that increasing iron doping induces the formation of iron-rich nanodomains embedded in the polymer matrix.

Propiedades El��ctricas en Membranas de Complejos Electrolitos Polim��ricos PVA-OH/LI2SO4/PEG400

Lithium ion conducting polymer electrolytes based on polyvinyl Alcohol (PVA-OH) complexed with salt Li2SO4 and different weight percent ratios of PEG(400) plasticizer have been prepared by solution cast technique using deionized water as solvent. The thermogravimetric analysis (TGA) showed that the thermal stability of the materials depended on the plasticizer content. The FTIR study confirmed the polymer salt complex formation. The modulus spectra indicated the non-Debye nature of the material; a dominant relaxation process is visible being associated with the dynamic glass transition, relaxation-a. The maximum of each peak is shifted to higher frequencies as the plasticizer increases due to an enhancement of dipolar mobility in the origin of cooperative motions. A power law frequency dependence of the real part of the electrical conductivity is observed, which is characteristic of the effects of ion-ion and/or ion-chain correlations in ion motion. This variation is well fitted to a Jonscher's expression.

Desenvolvimento de conjunto membrana-eletrodos para c��lula a combust��vel de metanol direto passiva

Direct methanol fuel cells (DMFCs) without external pumps or other ancillary devices for fuel and oxidant supply are known as passive DMFCs and are potential candidates to replace lithium-ion batteries in powering portable electronic devices. This paper presents the results obtained from a membrane electrode assembly (MEA) specifically designed for passive DMFCs. Appropriated electrocatalysts were prepared and the effect of their loadings was investigated. Two types of gas diffusion layers (GDL) were also tested. The influence of the methanol concentration was analyzed in each case. The best MEA performance presented a maximum power density of 11.94 mW cm^-2.

Electrode Materials for Ionic Liquid Based-Supercapacitors

The development of safe, high energy and power electrochemical energy-conversion systems can be a response to the worldwide demand for a clean and low-fuel-consuming transport. This thesis work, starting from a basic studies on the ionic liquid (IL) electrolytes and carbon electrodes and concluding with tests on large-size IL-based supercapacitor prototypes demonstrated that the IL-based asymmetric configuration (AEDLCs) is a powerful strategy to develop safe, high-energy supercapacitors that might compete with lithium-ion batteries in power assist-hybrid electric vehicles (HEVs). The increase of specific energy in EDLCs was achieved following three routes: i) the use of hydrophobic ionic liquids (ILs) as electrolytes; ii) the design and preparation of carbon electrode materials of tailored morphology and surface chemistry to feature high capacitance response in IL and iii) the asymmetric double-layer carbon supercapacitor configuration (AEDLC) which consists of assembling the supercapacitor with different carbon loadings at the two electrodes in order to exploit the wide electrochemical stability window (ESW) of IL and to reach high maximum cell voltage (Vmax). Among the various ILs investigated the N-methoxyethyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR1(2O1)TFSI) was selected because of its hydrophobicity and high thermal stability up to 350 ��C together with good conductivity and wide ESW, exploitable in a wide temperature range, below 0��C. For such exceptional properties PYR1(2O1)TFSI was used for the whole study to develop large size IL-based carbon supercapacitor prototype. This work also highlights that the use of ILs determines different chemical-physical properties at the interface electrode/electrolyte with respect to that formed by conventional electrolytes. Indeed, the absence of solvent in ILs makes the properties of the interface not mediated by the solvent and, thus, the dielectric constant and double-layer thickness strictly depend on the chemistry of the IL ions. The study of carbon electrode materials evidences several factors that have to be taken into account for designing performing carbon electrodes in IL. The heat-treatment in inert atmosphere of the activated carbon AC which gave ACT carbon featuring ca. 100 F/g in IL demonstrated the importance of surface chemistry in the capacitive response of the carbons in hydrophobic ILs. The tailored mesoporosity of the xerogel carbons is a key parameter to achieve high capacitance response. The CO2-treated xerogel carbon X3a featured a high specific capacitance of 120 F/g in PYR14TFSI, however, exhibiting high pore volume, an excess of IL is required to fill the pores with respect to that necessary for the charge-discharge process. Further advances were achieved with electrodes based on the disordered template carbon DTC7 with pore size distribution centred at 2.7 nm which featured a notably high specific capacitance of 140 F/g in PYR14TFSI and a moderate pore volume, V>1.5 nm of 0.70 cm3/g. This thesis work demonstrated that by means of the asymmetric configuration (AEDLC) it was possible to reach high cell voltage up to 3.9 V. Indeed, IL-based AEDLCs with the X3a or ACT carbon electrodes exhibited specific energy and power of ca. 30 Wh/kg and 10 kW/kg, respectively. The DTC7 carbon electrodes, featuring a capacitance response higher of 20%-40% than those of X3a and ACT, respectively, enabled the development of a PYR14TFSI-based AEDLC with specific energy and power of 47 Wh/kg and 13 kW/kg at 60��C with Vmax of 3.9 V. Given the availability of the ACT carbon (obtained from a commercial material), the PYR1(2O1)TFSI-based AEDLCs assembled with ACT carbon electrodes were selected within the EU ILHYPOS project for the development of large-size prototypes. This study demonstrated that PYR1(2O1)TFSI-based AEDLC can operate between -30��C and +60��C and its cycling stability was proved at 60��C up to 27,000 cycles with high Vmax up to 3.8 V. Such AEDLC was further investigated following USABC and DOE FreedomCAR reference protocols for HEV to evaluate its dynamic pulse-power and energy features. It was demonstrated that with Vmax of 3.7 V at T> 30 ��C the challenging energy and power targets stated by DOE for power-assist HEVs, and at T> 0 ��C the standards for the 12V-TSS and 42V-FSS and TPA 2s-pulse applications are satisfied, if the ratio wmodule/wSC = 2 is accomplished, which, however, is a very demanding condition. Finally, suggestions for further advances in IL-based AEDLC performance were found. Particularly, given that the main contribution to the ESR is the electrode charging resistance, which in turn is affected by the ionic resistance in the pores that is also modulated by pore length, the pore geometry is a key parameter in carbon design not only because it defines the carbon surface but also because it can differentially ���amplify��� the effect of IL conductivity on the electrode charging-discharging process and, thus, supercapacitor time constant.

Preparation of silicon-metal nanocomposites based on electrophoretic deposition

Silicon has long been considered as one of the most promising anode material for lithium-ion batteries. However, the poor cycle life due to stress during charge/discharge cycling has been a major concern for its practical applications. In this report, novel Si-metal nanocomposites have been explored to accommodate the stress generated in the intercalation process. Several approaches have been studied with the aim of getting uniform mixing, good mechanical stability and high Si content. Among the three approaches being investigated, Si- Galinstan nanocomposite based on electrophoretic deposition showed the best promise by achieving at least 32.3% Si theoretical weight percentage, and our in current experiments we���ve already get 13% Silicon weight percentage, which gave us an anode material 46% more capacity than the current commercial product.

Viabilidad t��cnica para la explotaci��n y separaci��n isot��pica de Li y prospectiva en el mercado de bater��as de ION-7Li y de 6Li como material base de dise��o en reactores de fusi��n nuclear

En claro alineamiento con estrategias de sostenibilidad en el uso de recursos naturales en un escenario constante de aumento de la demanda energ��tica mundial, el desarrollo de la tecnolog��a energ��tica en la Historia de la Especie Humana muestra un vector de evoluci��n permanente desde su origen en el sentido del desarrollo y uso de nuevas fuentes energ��ticas con la explotaci��n de recursos naturales de manera m��s eficiente: soluciones energ��ticas con aumento de la densidad energ��tica (exoenerg��a de proceso por unidad de masa de recurso natural). As�� el cambio de escala en la demanda de explotaci��n del Litio como recurso natural se viene presentando en la ��ltima d��cada ligada al desarrollo del mercado de las bater��as "ion-Litio" y los requisitos de combustible (Deuterio y Litio) en el camino de la fusi��n nuclear como opci��n energ��tica pr��xima. El an��lisis anticipado de las demandas sin��rgicas a escala de ambos mercados aparece de enorme inter��s prospectivo en sus aspectos t��cnicos: (1) tecnolog��as de base para la extracci��n mineral y de agua marina y (2) su enriquecimiento isot��pico (de inter��s sin��rgico; 7Li para bater��as eficientes ion-litio; 6Li como regenerador de tritio en ciclo de combustible en fusi��n nuclear) a la vez que en sus aspectos econ��micos. Este Proyecto realiza: (1) un ejercicio de an��lisis prospectivo de la demanda y de mercado para el enriquecimiento 6Li/7Li para las pr��ximas d��cadas, (2) se califican los desarrollos tecnol��gicos espec��ficos que van a poder permitir la producci��n a escala conforme a la demanda; (3) se selecciona y califica una t��cnica [de centrifugaci��n / termo-difusi��n/ destilaci��n combinada] como opci��n tecnol��gicamente viable para la producci��n a escala de formas litiadas; (4) se propone un dise��o conceptual de planta de producci��n y finalmente (5) propone un estudio de viabilidad para la demostraci��n de proceso y construcci��n de dicha planta de demostraci��n de la nueva capacidad tecnol��gica. ABSTRACT Clearly aligned with sustainability strategies under growing world energy demand in the use of natural resources the development of energy technology in the history of the human species shows a vector of ongoing evolution from its origin in the sense of the development and use of new energy sources with the exploitation of natural resources in a more efficient manner. The change of scale in the demand for exploitation of Lithium as a natural resource appears during the last decade as bound to the deployment of "lithium-ion" batteries market and to the Nuclear Fusion fuels (deuterium and lithium) supply scaled demands. The prospective analysis of demands to scale in both markets appears in scene with huge prospective interest in its technical aspects: (1) base technologies for mineral and water marine extraction (2) its isotopic enrichment (synergistic interests; 7Li efficient battery Li-ion; 6Li as fusion nuclear fuel breeder (tritium) as well as in its economic aspects. This Project: (1) propose a prospective analysis exercise of the synergistic supply demand for coming decades for the enrichment of 6Li and 7Li, (2) qualifies specific technological developments ongoing to respond to supply demand; (3) select and qualifies an appropriate technique [combined centrifugation/thermo-diffusion/distillation] as technologically viable option for lithiated forms scaled-production; (4) proposes a conceptual design of production plant based on the technique and finally (5) proposes a feasibility study for the process demonstration and construction of this new technological capability Demonstration Plant.

An open-source simulation tool of grid-connected PV systems.

This paper will present an open-source simulation tool, which is being developed in the frame of an European research project1. The tool, whose final version will be freely available through a website, allows the modelling and the design of different types of grid-connected PV systems, such as large grid-connected plants and building-integrated installations. The tool is based on previous software developed by the IES-UPM2, whose models and energy losses scenarios have been validated in the commissioning of PV projects3 carried out in Spain, Portugal, France and Italy, whose aggregated capacity is nearly 300MW. This link between design and commissioning is one of the key points of tool presented here, which is not usually addressed by present commercial software. The tool provides, among other simulation results, the energy yield, the analysis and breakdown of energy losses, and the estimations of financial returns adapted to the legal and financial frameworks of each European country. Besides, educational facilities will be developed and integrated in the tool, not only devoted to learn how to use this software, but also to train the users on the best design PV systems practices. The tool will also include the recommendation of several PV community experts, which have been invited to identify present necessities in the field of PV systems simulation. For example, the possibility of using meteorological forecasts as input data, or modelling the integration of large energy storage systems, such as vanadium redox or lithium-ion batteries. Finally, it is worth mentioning that during the verification and testing stages of this software development, it will be also open to the suggestions received from the different actors of the PV community, such as promoters, installers, consultants, etc.

Effect of composition, sonication and pressure on the rate capability of 5 V-LiNi0.5Mn1.5O4 composite cathodes

Positive composite electrodes having LiNi0.5Mn1.5O4 spinel as active material, a blend of graphite and carbon black for increasing the electrode electrical conductivity and either polyvinyldenefluoride (PVDF) or a blend of PVDF with a small amount of Teflon�� (1 wt%) for building up the electrode. They have been processed by tape casting on an aluminum foil as current collector using the doctor blade technique. Additionally, the component blends were either sonicated or not, and the processed electrodes were compacted or not under subsequent cold pressing. Composites electrodes with high weight, up to 17 mg/cm2, were prepared and studied as positive electrodes for lithium-ion batteries. The addition of Teflon�� and the application of the sonication treatment lead to uniform electrodes that are well-adhered to the aluminum foil. Both parameters contribute to improve the capacity drained at high rates (5C). Additional compaction of the electrode/aluminum assemblies remarkably enhances the electrode rate capabilities. At 5C rate, remarkable capacity retentions between 80% and 90% are found for electrodes with weights in the range 3���17 mg/cm2, having Teflon�� in their formulation, prepared after sonication of their component blends and compacted under 2 tonnes/cm2.

Ultra high temperature latent heat energy storage and thermophotovoltaic energy conversion

A conceptual energy storage system design that utilizes ultra high temperature phase change materials is presented. In this system, the energy is stored in the form of latent heat and converted to electricity upon demand by TPV (thermophotovoltaic) cells. Silicon is considered in this study as PCM (phase change material) due to its extremely high latent heat (1800 J/g or 500 Wh/kg), melting point (1410 C), thermal conductivity (~25 W/mK), low cost (less than $2/kg or $4/kWh) and abundance on earth. The proposed system enables an enormous thermal energy storage density of ~1 MWh/m3, which is 10e20 times higher than that of lead-acid batteries, 2e6 times than that of Li-ion batteries and 5e10 times than that of the current state of the art LHTES systems utilized in CSP (concentrated solar power) applications. The discharge efficiency of the system is ultimately determined by the TPV converter, which theoretically can exceed 50%. However, realistic discharge efficiencies utilizing single junction TPV cells are in the range of 20e45%, depending on the semiconductor bandgap and quality, and the photon recycling efficiency. This concept has the potential to achieve output electric energy densities in the range of 200-450 kWhe/m3, which is comparable to the best performing state of the art Lithium-ion batteries.

Investiga����o do mecanismo cin��tico da rea����o de redu����o de oxig��nio em solventes n��o aquosos

O aumento no consumo energ��tico e a crescente preocupa����o ambiental frente �� emiss��o de gases poluentes criam um apelo mundial favor��vel para pesquisas de novas tecnologias n��o poluentes de fontes de energia. Baterias recarreg��veis de l��tio-ar em solventes n��o aquosos possuem uma alta densidade de energia te��rica (5200 Wh kg-1), o que as tornam promissoras para aplica����o em dispositivos estacion��rios e em ve��culos el��tricos. Entretanto, muitos problemas relacionados ao c��todo necessitam ser contornados para permitir a aplica����o desta tecnologia, por exemplo, a baixa reversibilidade das rea����es, baixa pot��ncia e instabilidades dos materiais empregados nos eletrodos e dos solventes eletrol��ticos. Assim, neste trabalho um modelo cin��tico foi empregado para os dados experimentais de espectroscopia de imped��ncia eletroqu��mica, para a obten����o das constantes cin��ticas das etapas elementares do mecanismo da rea����o de redu����o de oxig��nio (RRO), o que permitiu investigar a influ��ncia de par��metros como o tipo e tamanho de part��cula do eletrocatalisador, o papel do solvente utilizado na RRO e compreender melhor as rea����es ocorridas no c��todo dessa bateria. A investiga����o inicial se deu com a utiliza����o de sistemas menos complexos como uma folha de platina ou eletrodo de carbono v��treo como eletrodos de trabalho em 1,2-dimetoxietano (DME)/perclorato de l��tio (LiClO4). A seguir, sistemas complexos com a presen��a de nanopart��culas de carbono favoreceu o processo de adsor����o das mol��culas de oxig��nio e aumentou ligeiramente (uma ordem de magnitude) a etapa de forma����o de super��xido de l��tio (etapa determinante de rea����o) quando comparada com os eletrodos de platina e carbono v��treo, atribu��da �� presen��a dos grupos laterais mediando �� transfer��ncia eletr��nica para as mol��culas de oxig��nio. No entanto, foi observada uma r��pida passiva����o da superf��cie eletrocatal��tica atrav��s da forma����o de filmes finos de Li2O2 e Li2CO3 aumentando o sobrepotencial da bateria durante a carga (diferen��a de potencial entre a carga e descarga > 1 V). Adicionalmente, a incorpora����o das nanopart��culas de platina (Ptnp), ao inv��s da folha de platina, resultou no aumento da constante cin��tica da etapa determinante da rea����o em duas ordens de magnitude, o qual pode ser atribu��do a uma mudan��a das propriedades eletr��nicas na banda d met��lica em fun����o do tamanho nanom��trico das part��culas, e estas modifica����es contribu��ram para uma melhor efici��ncia energ��tica quando comparado ao sistema sem a presen��a de eletrocatalisador. Entretanto, as Ptnp se mostraram n��o espec��ficas para a RRO, catalisando as rea����es de degrada����o do solvente eletrol��tico e diminuindo rapidamente a efici��ncia energ��tica do dispositivo pr��tico, devido ao ac��mulo de material no eletrodo. O emprego de l��quido i��nico como solvente eletrol��tico, ao inv��s de DME, promoveu uma maior estabiliza����o do intermedi��rio super��xido formado na primeira etapa de transfer��ncia eletr��nica, devido �� intera����o com os c��tions do l��quido i��nico em solu����o, o qual resultou em um valor de constante cin��tica da forma����o do super��xido de tr��s ordens de magnitude maior que o obtido com o mesmo eletrodo de carbono v��treo em DME, al��m de diminuir as rea����es de degrada����o do solvente. Estes fatores podem contribuir para uma maior pot��ncia e ciclabilidade da bateria de l��tio-ar operando com l��quidos i��nicos.

Dense carbon monoliths for supercapacitors with outstanding volumetric capacitances

A commercially available dense carbon monolith (CM) and four carbon monoliths obtained from it have been studied as electrochemical capacitor electrodes in a two-electrode cell. CM has: (i) very high density (1.17 g cm���3), (ii) high electrical conductivity (9.3 S cm���1), (iii) well-compacted and interconnected carbon spheres, (iv) homogeneous microporous structure and (v) apparent BET surface area of 957 m2g���1. It presents interesting electrochemical behaviors (e.g., excellent gravimetric capacitance and outstanding volumetric capacitance). The textural characteristics of CM (porosity and surface chemistry) have been modified by means of different treatments. The electrochemical performances of the starting and treated monoliths have been analyzed as a function of their porous textures and surface chemistry, both on gravimetric and volumetric basis. The monoliths present high specific and volumetric capacitances (292 F g���1 and 342 F cm���3), high energy densities (38 Wh kg���1 and 44 Wh L���1), and high power densities (176 W kg���1 and 183 W L���1). The specific and volumetric capacitances, especially the volumetric capacitance, are the highest ever reported for carbon monoliths. The high values are achieved due to a suitable combination of density, electrical conductivity, porosity and oxygen surface content.