Manufacture Of Carbon Electrodes Research Articles

ХАРАКТЕРИЗАЦИЯ УГЛЕРОДНЫХ ЭЛЕКТРОДОВ С НАНОЧАСТИЦАМИ ГИДРОКСИД НИКЕЛЯ ДЛЯ СУПЕРКОНДЕНСАТОРОВ(CHARACTERIZATION OF CARBON ELECTRODES WITH NANOPARTICLES OF NICKEL HYDROXIDE FOR SUPERCONDENSERS)

Composite electrodes for supercapacitors have been obtained, consisting of a matrix of highly dispersed carbon materials: microcrystalline graphite and multi-walled carbon nanotubes, also a filler of nanoparticles of nickel hydroxide. Β-Co (OH) 2 and β-Ni (OH) 2 nanopowders were obtained by chemical deposition from solution. To create the electrodes, a polyvinylidene fluoride polymer in the form of a powder was used as a bonding material. The main technological stages of the manufacture of electrodes were determined, the parameters of the obtained structures were measured by the method of cyclic voltammetry and galvanostatic charge-discharge. For the manufacture of carbon electrodes, the optimal ratios of highly dispersed carbon materials, a binder polymer and a solvent have been determined to create mechanically strong layers with high conductivity and capacity. The technique of creating capacitor structures and measuring the capacitance of the obtained electrochemical capacitors has been worked out. Capacitors made of highly dispersed carbon materials showed typical rectangular curves of cyclic voltammetry and a linear decay-rise of the galvanostatic charge-discharge dependences. Typical values of specific capacity ~ 50 F / g were obtained. Composite electrodes made of nickel hydroxide nanoparticles in a carbon matrix demonstrated an increase in capacitance to ~ 180 F / g. It is shown that composite electrodes are promising for creating capacitors with a high specific capacity.

ХАРАКТЕРИЗАЦИЯ УГЛЕРОДНЫХ ЭЛЕКТРОДОВ С НАНОЧАСТИЦАМИ ГИДРОКСИД НИКЕЛЯ ДЛЯ СУПЕРКОНДЕНСАТОРОВ (CHARACTERIZATION OF CARBON ELECTRODES WITH NANOPARTICLES OF NICKEL HYDROXIDE FOR SUPERCONDENSERS)

Composite electrodes for supercapacitors have been obtained, consisting of a matrix of highly dispersed carbon materials: microcrystalline graphite and multi-walled carbon nanotubes, also a filler of nanoparticles of nickel hydroxide. Β-Co (OH) 2 and β-Ni (OH) 2 nanopowders were obtained by chemical deposition from solution. To create the electrodes, a polyvinylidene fluoride polymer in the form of a powder was used as a bonding material. The main technological stages of the manufacture of electrodes were determined, the parameters of the obtained structures were measured by the method of cyclic voltammetry and galvanostatic charge-discharge. For the manufacture of carbon electrodes, the optimal ratios of highly dispersed carbon materials, a binder polymer and a solvent have been determined to create mechanically strong layers with high conductivity and capacity. The technique of creating capacitor structures and measuring the capacitance of the obtained electrochemical capacitors has been worked out. Capacitors made of highly dispersed carbon materials showed typical rectangular curves of cyclic voltammetry and a linear decay-rise of the galvanostatic charge-discharge dependences. Typical values of specific capacity ~ 50 F / g were obtained. Composite electrodes made of nickel hydroxide nanoparticles in a carbon matrix demonstrated an increase in capacitance to ~ 180 F / g. It is shown that composite electrodes are promising for creating capacitors with a high specific capacity.

Synthesis of activated carbon monolith derived from cocoa pods for supercapacitor electrodes application

ABSTRACT Agricultural and agro-industrial residues are ordinary wastes in the forestry industry and their valorization is an important issue.Cocoa (Theobroma cacao) pods waste was chosen as an activated activated carbon material and studied as active materials for supercapacitor electrodes. The carbon electrode has been made using 0.3 M and 0.4 M Potassium Hydroxide (KOH) activators at 700°C. Physical properties were tested by measuring density, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM), while the electrochemical properties were tested using the Cyclic Voltammetry (CV) method. Activated carbon electrodes were constructed by a combination of chemical activation, and physical activation methods. The technique of making carbon electrodes was started from pre-carbonization, milling, chemical activation, pellet making, carbonization, and physical activation. Analysis of dimensions, density, and specific capacitance in the manufacture of carbon electrodes showed the mass, diameter, thickness, and density of the electrodes decreased with the addition of KOH concentrations from 0.3 M to 0.4 M. While the specific capacitance value of the electrode was directly proportional to the increase of KOH concentration. In XRD measurement data, the values of 2θ in the range of 23.569°–24.747° was obtained for the reflection field 002, and 44.634°–44.781° for the reflection plane 100. X-ray diffraction curve data showed a 0.4 M at 700°C sample having an Lc value and a lattice distance smaller than the sample of 0.3 M at 700°C. Therefore, it could be indicated that the surface area of the sample of 0.4 M at 700°C was greater than the sample of 0.3 M at 700°C. The electrochemical test showed that the method of chemical activation variation of 0.4 M produced electrodes with better performance than 0.3 M. The specific capacitance value obtained at a concentration of 0.3 M was 90.2 F/gr with a density of 0.850 gr/cm3, while at a concentration of 0.4 M was 140.2 F/gr with a density of 0.802 gr/cm3. These results indicate the high potential of agricultural cocoa pods based activated carbon monoliths as supercapacitor electrode.

Electrospun Enzymatic Hydrolysis Lignin-Based Carbon Nanofibers as Binder-Free Supercapacitor Electrodes with High Performance.

Carbon nanofibers consisting of Poly(acrylonitrile) (PAN) and enzymatic hydrolysis lignin (EHL) were prepared in the present study by electrospinning followed by stabilization in air and carbonization in N2 environment. The morphology and structure of the electrospun carbon nanofibers were characterized by Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET), Roman, and the electrochemical performances were then evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS)methods. When the amount of EHL was 60 wt. %, the as-prepared nanofibers have the smallest average diameter of 172 nm and the largest BET specific surface area of 675 m2/g without activating treatment. The carbon nanofiber electrode showed excellent specific capacitance of 216.8 F/g at the current density of 1 A/g, maintaining 88.8% capacitance retention after 2000 cycles. Moreover, the carbon nanofiber electrode containing 60 wt. % exhibited a smaller time constant (0.5 s) in comparison to that of carbon nanofibers in literatures. These findings suggest the potential use of EHL could be a practical as a sustainable alternative for PAN in carbon electrode manufacturing.

Melvin B. Redmount

Melvin B. Redmount, 90, died on Nov. 11, 2016, in Ridgway, Pa. “Melvin was a recognized expert in carbon electrode manufacturing, servicing companies in the iron and steel industry. He worked most of his career for Airco Carbon (later, part of British Oxygen) and in his retirement, worked as a consultant for Showa Denko in South Carolina. He was active in animal protection charities, local science fairs, community theater, and in his later years, family genealogy.”—Joel Redmount, son Most recent title: director of forward planning, Airco Carbon Education: B.S., chemical engineering, Pennsylvania State University, 1948; M.S., chemical engineering, Brooklyn Polytechnic Institute, 1950 Survivors: daughter, Esther; sons, Ian and Joel To recognize your late loved one or colleague, submit obituary information at cenm.ag/obits.

Thermomechanical characterisation of coal tar pitch- based carbon containing SiC nanoparticles

Coal tar pitch (CTP) modified with silicon carbide nanoparticles (nSiC) was used as a carbon binder precursor for the manufacture of carbon materials. Carbon samples were prepared in the form of a composition consisting of synthetic coke, graphite and nSiC- modified CTP prior to heat treatment at temperatures from 800°C to 2800°C. The effect of ceramic nanofiller in CTP on oxidation resistance of carbon samples obtained at various temperatures was studied. Physical and mechanical properties of carbon samples obtained at 2000°C and 2800°C were analysed. nSiC presence in CTP was found to change the elevated temperature properties of carbon samples. The oxidation tests conducted at 600°C in air showed a significant improvement of the resistance of carbon samples modified with small amount of nSiC and annealed at 2000°C. Properties investigated included characteristics important for application of carbon materials for carbon electrode manufacturing, i.e., electrical and thermal conductivities as well as mechanical properties. Due to microstructural changes of carbon samples in the presence of nSiC filler physical and mechanical properties improved after annealing the samples at high temperature in comparison to unmodified carbon samples.

EFFECTS OF HEATING TEMPERATURE AND BINDER IN THE PRODUCTION OF CHAR-BASED ELECTRICAL CONDUCTOR

<p class="TTPTitle"><em><span lang="IN">Graphite as one alotrof carbon is widely used as an electrode material for a good electrical conductivity properties. Charcoal as a carbon source material was found very abundant in nature. Charcoal has the potential application for electrode material in energy storage such as in a battery or supercapacitor. For this purpose, charcoal amorphous structure needs to be converted into a graphite structure so that it has better electrical conductivity property. This research aims to prepare the electrical conductor material derived from wood charcoal that could potentially be used as an electrode. Preparation was made by mixing charcoal powder with asphalt binder with a weight ratio of 3:1, 4:1, 5:1 and followed by heat treatment under an inert atmosphere at temperature of 600°C, 800°C and 1000°C. Charcoal material which was originally to be an electrical insulator has been successfully converted into an electrical conductor. The achievement of the optimum temperature to produce electrodes with the smallest electrical resistance is then applied to the manufacture of carbon electrodes by heating a mixture of charcoal and fructose binder in a weight ratio of 1:1 (w/w). The results showed electrodes with a mixture of charcoal powder and fructose with heat treatment at 1000°C has the better electrical conductivity among other variations.</span></em></p>

EFFECTS OF HEATING TEMPERATURE AND BINDER IN THE PRODUCTION OF CHAR-BASED ELECTRICAL CONDUCTOR

<p class="TTPTitle"><em><span lang="IN">Graphite as one alotrof carbon is widely used as an electrode material for a good electrical conductivity properties. Charcoal as a carbon source material was found very abundant in nature. Charcoal has the potential application for electrode material in energy storage such as in a battery or supercapacitor. For this purpose, charcoal amorphous structure needs to be converted into a graphite structure so that it has better electrical conductivity property. This research aims to prepare the electrical conductor material derived from wood charcoal that could potentially be used as an electrode. Preparation was made by mixing charcoal powder with asphalt binder with a weight ratio of 3:1, 4:1, 5:1 and followed by heat treatment under an inert atmosphere at temperature of 600°C, 800°C and 1000°C. Charcoal material which was originally to be an electrical insulator has been successfully converted into an electrical conductor. The achievement of the optimum temperature to produce electrodes with the smallest electrical resistance is then applied to the manufacture of carbon electrodes by heating a mixture of charcoal and fructose binder in a weight ratio of 1:1 (w/w). The results showed electrodes with a mixture of charcoal powder and fructose with heat treatment at 1000°C has the better electrical conductivity among other variations.</span></em></p>

Occupational exposure to polycyclic aromatic hydrocarbons and lymphatic and hematopoietic neoplasms: a systematic review and meta-analysis of cohort studies.

Data on the risk of lymphatic and hematopoietic neoplasms among workers whose jobs entail high exposure to polycyclic aromatic hydrocarbons (PAH) are sparse, and mainly based on small-size studies. We carried out a systematic review of occupational cohort studies that reported results on incidence or mortality from Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), leukemia or multiple myeloma (MM) among workers exposed to PAH. We computed meta-analytic estimates using a random effect model. Meta-relative risk (meta-RR) was computed separately by each type of neoplasm, job or industry. We identified 41 studies (12 in iron and steel foundries, 11 in aluminum plant, 6 in cokeries, 6 in carbon electrode manufacturing, 2 on asphalt workers, 2 on creosote-exposed workers, 1 on tar distillery workers and 1 evaluating both tar distillery workers and roofers). No significant excess risk of any lymphatic and hematopoietic neoplasms was found among workers employed in jobs or industries entailing high PAH exposure. Among 18 meta-analytic estimates by job or industry and type of neoplasm, 16 were close to unit, i.e., between 0.72 and 1.27, whereas the meta-RR was 1.38 [95% confidence interval (CI) 0.95-2.01] for HL in foundry workers and 2.01 (95% CI 0.96-4.22) for NHL in workers exposed to creosote. There was no association between occupation entailing high PAH exposure and risk of MM or leukemia.

Improved technology for manufacture of carbon electrodes

Improved technology for manufacture of carbon electrodes

Improved technology for manufacture of carbon electrodes

Current industrial carbon electrodes are typically manufactured by blending petroleum coke particles (the filler) with molten coal tar pitch (the binder) and extruding the resultant mix to form the ‘green electrode’. This is then baked under controlled conditions. In case of usage as anodes in steel electric furnaces (or as other carbon and graphite products), the electrodes could undergo further processing like pitch impregnation or graphitization. During heat treatment, some of the organics are destructively distilled, vaporized or decomposed, resulting in carbon deposition in the electrode. As the vaporized materials exit the body of the electrode they cause porosity in the walls, which results in reduction in density, current carrying capacity and flexural strength. The paper presents investigations to improve some physico-chemical characteristics of these electrodes (such as coefficient of thermal expansion, mechanical strengths, density, pore volume, porosity etc.), obtained in different manufacture steps, by addition of varieties of coal tar pitch. These include attempts to improve the chemical compatibility of the coke-pitch system in the mixture and establish the method and the point of introduction of additive, the concentration required and appropriate analytical control during the entire manufacture. Methods of analysis used include thermogravimetry and porosimetry. The microstructure of the electrodes is investigated through a wide range and the data obtained include pore size and pore volume distribution, surface area, porosity, particle size distribution and type of pores. The overall results clearly indicate better characteristics and performance for electrodes with additives as against electrodes without them, such as lower porosity, lower thermal expansion coefficients and greater mechanical strength. These data are analyzed with respect to the process step and electrode type.

Monitoring of occupational exposure to polycyclic aromatic hydrocarbons in a carbon-electrode manufacturing plant

An investigation is presented of occupational exposure to polycyclic aromatic hydrocarbons (PAH) in a carbon-electrode manufacturing plant, as assessed by three monitoring methods, viz. environmental monitoring of the external dose by analysis of personal air samples, biological monitoring of the internal dose by analysis of urinary 1-hydroxypyrene (1-OHpyrene), and biological effect monitoring by dosimetry of PAH-DNA adducts in blood lymphocytes. On the basis of job conditions, workers at the plant were divided into three groups with presumed low, intermediate and high exposure to air-borne PAH, respectively. All air samples showed levels of total PAH below the current MAC-value in the Netherlands, which is 200 μg/m3, whereas the benzo[a]pyrene level was occasionally higher than the recommended concentration of 2 μg/m3. The values of 1-OHpyrene in urine from the intermediate and high exposure groups were significantly higher than those of the low exposure group, namely 3.6- and 8.2-fold, respectively. Clear external and internal exposure was thus demonstrated for workers of the high and intermediate exposure groups, but this did not result in a measurable effect at the DNA level in blood lymphocytes. Tobacco smoking, on the other hand, caused a significant increase of the levels of PAH-DNA adducts but did not affect 1-OHpyrene values. These data suggest that smoking is a more important risk factor for adverse health effects, i.e. cancer, than occupational exposure to PAH in this plant.

Monitoring of Occupational Exposure to Polycyclic Aromatic Hydrocarbons in a Carbon-electrode Manufacturing Plant

An investigation is presented of occupational exposure to polycyclic aromatic hydrocarbons (PAH) in a carbon-electrode manufacturing plant, as assessed by three monitoring methods, viz. environmental monitoring of the external dose by analysis of personal air samples, biological monitoring of the internal dose by analysis of urinary 1-hydroxypyrene (1-OHpyrene), and biological effect monitoring by dosimetry of PAH-DNA adducts in blood lymphocytes. On the basis of job conditions, workers at the plant were divided into three groups with presumed low, intermediate and high exposure to air-borne PAH, respectively. All air samples showed levels of total PAH below the current MAC-value in the Netherlands, which is 200µg/m3, whereas the benzo[a]pyrene level was occasionally higher than the recommended concentration of 2 µg/m3 The values of 1-OHpyrene in urine from the intermediate and high exposure groups were significantly higher than those of the low exposure group, namely 3.6- and 8.2-fold, respectively. Clear external and internal exposure was thus demonstrated for workers of the high and intermediate exposure groups, but this did not result in a measurable effect at the DNA level in blood lymphocytes. Tobacco smoking, on the other hand, caused a significant increase of the levels of PAH-DNA adducts but did not affect 1 -OHpyrene values. These data suggest that smoking is a more important risk factor for adverse health effects, i.e. cancer, than occupational exposure to PAH in this plant. © 1998 British Occupational Hygiene Society. Published by Elsevier Science Ltd.

The use of benzo[ a]pyrene diolepoxide-modified DNA standards for adduct quantification in 32P-postlabelling to assess exposure to polycyclic aromatic hydrocarbons: application in a biomonitoring study

The 32P-postlabelling assay is one of the most sensitive methods for detection of DNA adducts induced by exposure to genotoxic chemicals. Under optimal conditions, detection limits of one adduct per 10 9–10 10 nucleotides have been reported. This sensitivity now allows monitoring of occupational and even environmental exposure of humans to certain classes of chemicals, mainly polycyclic aromatic hydrocarbons (PAH). Despite its widespread use, 32P-postlabelling is still not a standardized method. Rigorous interlaboratory comparisons are scarce, and those that have been undertaken often show rather different results, both in relative and in absolute values, for the amounts of DNA adducts in the same samples. Furthermore, the optimization of many steps in the procedure has still not been given adequate attention. This paper deals with some technical aspects of detection of PAH–DNA adducts by 32P-postlabelling, in particular with assay calibration and adduct quantification. For this purpose, benzo[ a]pyrene (BP)-modified DNA standards were prepared, the adduct contents of which were determined by use of an independent fluorometric method, viz. synchronous fluorescence spectrophotometry (SFS). These BP–DNA standards are processed along with the test samples throughout the entire 32P-postlabelling procedure, from the enzymic digestion up to and including the determination of radioactivity in adduct spots on the chromatogram. As such, these reference samples can be considered as external standards for inter-assay calibration. This method for adduct quantification was compared with the commonly used relative adduct labelling (RAL) and comparative dAMP labelling, which appeared to give rise to an underestimation of adduct levels. The method was applied in a biomonitoring study among workers in a carbon-electrode manufacturing plant, exposed to PAH. Although DNA adduct levels in peripheral blood lymphocytes of exposed workers, as determined by 32P-postlabelling, were not significantly different from those of controls, a significant difference was seen when smokers and non-smokers were compared.

Pneumoconiosis in carbon electrode workers.

Pneumoconiosis was diagnosed in five workers involved in the manufacture of carbon electrodes. Possible etiologies are discussed. It is generally believed that pneumoconiosis ceased to be a problem in this industry after World War II; however, the reported cases all resulted from exposures after 1940. These findings question the efficacy of recent and current engineering controls and suggest the need for further study of this industry.

Influence of the quinoline-insoluble matter in pitch on carbonization behaviour and structure of pitch coke

The influence of the quinoline-insoluble matter in pitch on the carbonization behaviour and especially on the pitch-coke properties is of basic interest both for the production of pitch coke and the manufacture of carbon electrodes. A more isotropic coke is produced by increasing the amount of quinoline-insolubles. The coefficient of thermal expansion (CTE) by volume measured directly at the coke particle is strongly influenced by the type of quinoline-insoluble. A larger amount of the primary type of quinoline-insolubles causes a large increase of the CTE (volume) from 3.2 to 17.4 × 10 −6 K −1, whereas the secondary type influences the CTE only slightly. This strong influence of quinoline-insolubles on the structure of pitch-binder coke results in a remarkable increase of mechanical strength of carbon artefacts.

The porosity of brown-coal char

A report on the results of measurements of the internal porosity of chars made from Yallourn brown coal, and the outcome of efforts made to reduce this porosity down to the figure obtained with petroleum coke by briquetting and/or carbonizing procedures. The work reported is part of a wider assessment of the suitability of such chars as a filler material for the manufacture of carbon electrodes used in aluminium smelting.

Pneumoconiosis in Carbon Electrode Makers

In the absence of adequate preventive measures the manufacture of carbon electrodes is attended by a considerable dust hazard. The present paper is based on a study of the clinical, radiological, and pathological changes resulting from inhalation of this dust, which is derived from crushed coke and anthracite. An account is given of the findings in a clinical survey of 15 men who had been employed for at least 10 years in manufacturing carbon electrodes. Four of these men were suffering from complicated and five from simple pneumoconiosis. In addition, the findings in three necropsied cases (two complicated and one simple) are recorded in detail. Bacteriological examination of the lungs and analysis of the lung dust was carried out in the two cases of complicated pneumoconiosis. It is shown that carbon electrode makers may develop simple pneumoconiosis with focal emphysema and that this may complicated by the development of massive fibrotic lesions. Both the simple and the complicated pneumoconiosis are indistinguishable from the corresponding conditions in other coalworkers. Quartz was almost entirely absent from the lung dust of the two necropsied cases with massive fibrosis and in one of these cases virulent tubercle bacilli were shown. The significance of these findings is discussed in relation to the aetiology of progressive massive fibrosis. While it is evident that they are incompatible with the “silica” theory they provide some limited support for the “tuberculosis” theory.

Pneumoconiosis in carbon electrode makers.

In the absence of adequate preventive measures the manufacture of carbon electrodes is attended by a considerable dust hazard. The present paper is based on a study of the clinical, radiological, and pathological changes resulting from inhalation of this dust, which is derived from crushed coke and anthracite. An account is given of the findings in a clinical survey of 15 men who had been employed for at least 10 years in manufacturing carbon electrodes. Four of these men were suffering from complicated and five from simple pneumoconiosis. In addition, the findings in three necropsied cases (two complicated and one simple) are recorded in detail. Bacteriological examination of the lungs and analysis of the lung dust was carried out in the two cases of complicated pneumoconiosis. It is shown that carbon electrode makers may develop simple pneumoconiosis with focal emphysema and that this may complicated by the development of massive fibrotic lesions. Both the simple and the complicated pneumoconiosis are indistinguishable from the corresponding conditions in other coalworkers. Quartz was almost entirely absent from the lung dust of the two necropsied cases with massive fibrosis and in one of these cases virulent tubercle bacilli were shown. The significance of these findings is discussed in relation to the aetiology of progressive massive fibrosis. While it is evident that they are incompatible with the “silica” theory they provide some limited support for the “tuberculosis” theory.

The Manufacture of Carbon Electrodes.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Manufacture of Carbon Electrodes.G. A. RoushCite this: Ind. Eng. Chem. 1909, 1, 5, 286–295Publication Date (Print):May 1, 1909Publication History Published online1 May 2002Published inissue 1 May 1909https://doi.org/10.1021/ie50005a002RIGHTS & PERMISSIONSArticle Views65Altmetric-Citations4LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (918 KB) Get e-Alerts