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Full-Text Articles in Engineering

Battery Design, Construction, And Characterization For Small Motor Use Focusing On Anodic Zinc For Electron Flow, Amber Veach May 2023

Battery Design, Construction, And Characterization For Small Motor Use Focusing On Anodic Zinc For Electron Flow, Amber Veach

Chemical Engineering Undergraduate Honors Theses

This thesis explores the construction, characterization, and application of anodic zinc batteries for powering a small electric motor for the ChemE Car competition. Two zinc galvanic cell batteries were studied: zinc-carbon and zinc-air batteries. Prototype batteries were constructed and tested for voltage, amperage, and power production. In the zinc-carbon trials, a 3:1 mixture of manganese dioxide and graphite was determined to be the best cathode for power production. The size which allowed for sufficient power while maintaining the smallest footprint on the car was a zinc can six cm tall and two cm in diameter. Analysis of paper zinc-air battery …


Direct Air Capture: Catalyzing A Carbon Negative Future, Tagg K. Lee Jan 2023

Direct Air Capture: Catalyzing A Carbon Negative Future, Tagg K. Lee

Civil and Environmental Engineering Publications

Direct Air Capture (DAC) technology has emerged as a promising means to address the escalating challenges of atmospheric carbon dioxide (CO2) levels and mitigate climate change. This paper provides an elementary overview of DAC, encompassing its underlying principles, technological advancements, and associated challenges. Point Source Carbon Capture is compared against Direct Air Capture with a solid or liquid sorbent, and physisorbents/chemisorbents are outlined. The past decade has seen a steep rise in the usage of chemical sorbents in particular, which are explored alongside their regeneration processes. This review provides an introductory explanation for the mechanisms of common DAC …


Development Of Novel Catalysts For Hydrogen Gas Production From Biomass Compounds, Boanerges Bamaca Aug 2020

Development Of Novel Catalysts For Hydrogen Gas Production From Biomass Compounds, Boanerges Bamaca

Department of Biological Systems Engineering: Dissertations and Theses

Hydrothermal biomass gasification technologies (sub- and supercritical water gasification and aqueous-phase reforming) have considerable economic, environmental, and technical advantages over other energy-extensive technologies (e.g. natural gas reforming) for hydrogen gas production. However, lack of economically feasible and highly active catalysts is a main challenge that impedes upscaling of these technologies for hydrogen gas production.

The goal of this study was to develop innovative, economically feasible and active heterogeneous supported metal catalysts for hydrothermal processes for producing hydrogen gas from biomass-derived compounds. Because of its stable structure and chemical inertness, graphene was used as catalyst support. Graphene supported metal catalysts were …


Investigation Of Oxidized Carbon Supported Au Catalysts Synthesized Via Strong Electrostatic Adsorption Of Au(En)2Cl3 For The Hydrochlorination Of Acetylene To Vinyl Chloride Monomer, Sean Reginald Noble Jul 2020

Investigation Of Oxidized Carbon Supported Au Catalysts Synthesized Via Strong Electrostatic Adsorption Of Au(En)2Cl3 For The Hydrochlorination Of Acetylene To Vinyl Chloride Monomer, Sean Reginald Noble

Theses and Dissertations

Over 20 million tons of vinyl chloride monomer (VCM) is produced every year using acetylene hydrochlorination using a supported mercuric chloride catalyst. During this process mercury is reduced and sublimes into the environment harming all living animals and humans, so carbon-supported Au catalysts have been developed in attempts to replace it. Various techniques have been used to make these catalysts including several variations of dry impregnation. In this study we investigate the ability of Strong Electrostatic Adsorption (SEA) of Au(en)2Cl3 onto various supports to demonstrate the ability to rationally and consistently synthesize gold catalysts with ultra-small particle …


Brominated Carbon Materials As Positive Electrodes For Nonaqueous Secondary Lithium-Bromine Batteries, Benjamin Beau Peterson Jun 2020

Brominated Carbon Materials As Positive Electrodes For Nonaqueous Secondary Lithium-Bromine Batteries, Benjamin Beau Peterson

LSU Doctoral Dissertations

Secondary lithium-bromine (Li-Br2) batteries have theoretical potentials near 4.1 V vs Li/Li+ and capacities more than 2 times greater than conventional Li-ion batteries. Herein, secondary, non-aqueous Li-Br2 half-cell batteries are reported using a Li metal anode, carbon-coated glass fiber separator, non-aqueous Li-based electrolytes with and without the addition of lithium bromine (LiBr) salt, and positive electrodes consisting of either chemically brominated non-graphitic carbon or carbon derived from the carbonization of metal-organic frameworks (MOFs) with LiBr embedded into the micro- and mesopores of the carbon matrix. The separator is effective in mitigating the transport of Br2 …


Carbon-Based Artificial Sei Layers For Aqueous Lithium-Ion Battery Anodes, Usha Subramanya, Charleston Chua, Victor Gin He Leong, Ryan Robinson, Gwenlyn Cruz Cabiltes, Prakirti Singh, Bonnie Yip, Anuja Bokare, Folarin Erogbogbo, Dahyun Oh Jan 2020

Carbon-Based Artificial Sei Layers For Aqueous Lithium-Ion Battery Anodes, Usha Subramanya, Charleston Chua, Victor Gin He Leong, Ryan Robinson, Gwenlyn Cruz Cabiltes, Prakirti Singh, Bonnie Yip, Anuja Bokare, Folarin Erogbogbo, Dahyun Oh

Faculty Publications

Replacing flammable organic electrolytes with aqueous electrolytes in lithium-ion batteries (LIB) can greatly enhance the safety of next-generation energy storage systems. With the extended electrochemical stability window of electrolytes, 'water-in-salt' (WIS) electrolytes containing LIB presented significant performance improvements. However, the solubility limits of lithium salts in water restrain the extent of kinetic protection offered by the high salt concentration. Here, we report design strategies of anode structure to improve the cycle life of LIB with WIS electrolytes. We introduced partially graphitic protective carbon layers on anode particles using a versatile coating method. This protective layer not only improved charge transfer …


Improving The Distribution And Use Of Biogas By Conversion To Methanol, Zachary Christman Mar 2019

Improving The Distribution And Use Of Biogas By Conversion To Methanol, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In this technology review, the process of turning an average biogas into methanol will be presented. The purpose is to find a better method of transporting the energy contained within biogas so that it may be used in industry as a value added product. The first step is removal of hydrogen sulfide, a corrosive chemical that can breakdown mechanical parts. The second step is carbon capture and conversion of the biogas into hydrogen. The final step is the hydrogenation of carbon dioxide into methanol using a copper catalyst and an alcohol co-catalyst.


New Method Of Manufacturing Carbon Foam, Matthew D. Artimez Jan 2019

New Method Of Manufacturing Carbon Foam, Matthew D. Artimez

Graduate Theses, Dissertations, and Problem Reports

Carbon foam is a product that has some unique features. Carbon foam is a light weight material that has a high crush strength. It is electrically conductive, but because it is composed of air space between the tendrils, it is not a thermal conductor. Since it contains no volatile content, it is noncombustible. All these features allow carbon foam to have many modern applications. Currently, there are only three methods of producing carbon foam, and all three are not cost- efficient enough to meet the demand of potential new markets.

In this thesis, a new procedure of producing carbon foam …


Acid Treated Carbon As Anodic Electrocatalysts Toward Direct Ascorbic Acid Alkaline Membrane Fuel Cells, He-Mu Chen, Chen-Xi Qiu, Yuan-Yuan Cong, Hui-Yuan Liu, Zi-Hui Zhai, Yu-Jiang Song Dec 2018

Acid Treated Carbon As Anodic Electrocatalysts Toward Direct Ascorbic Acid Alkaline Membrane Fuel Cells, He-Mu Chen, Chen-Xi Qiu, Yuan-Yuan Cong, Hui-Yuan Liu, Zi-Hui Zhai, Yu-Jiang Song

Journal of Electrochemistry

In order to improve the hydrophilicity and electrocatalytic activity, commercial carbon black (BP 2000) was subjected to acid treatment to obtain acid-treated carbon (ATC). The generation of rich oxygen-containing groups on the surface of the ATC was proved by X-ray photoelectron spectra (XPS), Fourier transform-infra red spectra (FTIR), thermogravimetric analysis (TG) and contact angle measurement. UV-vis spectra were firstly recorded to calculate activation energy (Ea) of ascorbic acid (AA) chemical oxidation in alkaline conditions by oxygen in air and the Ea value was determined to be 37.1 kJ·mol-1. Additionally, electrochemical impedance spectra (EIS) were used to evaluate unprecedented …


Wafer Enhanced Electrodeionization For Conversion Of Co2 Into Bicarbonate Feed For Algae Cultured Photobioreactors, Kayvan Afrasiabi May 2018

Wafer Enhanced Electrodeionization For Conversion Of Co2 Into Bicarbonate Feed For Algae Cultured Photobioreactors, Kayvan Afrasiabi

Chemical Engineering Undergraduate Honors Theses

The world has acknowledged climate change as a global crisis that demands considerable attention, with one of the largest culprit being carbon emissions from industrial processing and power generation. While reduction in carbon emissions is the principal action towards mitigating the effects of climate change, scientists and engineers have given increased attention to alternative sources of energy as well as methods of carbon sequestration to coax traditional manufactory and industry into environmentally friendly and sustainable practices. One technology of this nature is the use of wafer-enhanced electrodeionization (WE-EDI) membranes to convert gaseous carbon dioxide (CO2) from industrial flue …


Hydrodeoxygenation Of Acetic Acid Using Monometallic And Bimetallic Catalysts Supported On Carbon, José Luis Contreras Mora Jan 2018

Hydrodeoxygenation Of Acetic Acid Using Monometallic And Bimetallic Catalysts Supported On Carbon, José Luis Contreras Mora

Theses and Dissertations

Heterogeneous catalytic hydrodeoxygenation (HDO) of biomass-derived feeds is a deoxygenation process that is of highly interest. Carboxylic acids are one of the main components of bio-oils and acetic acid is one of the most abundant of these carboxylic acids. This acid is rich in oxygen, therefore a lot of research to produce fuel and other valuable chemicals such as ethanol is of interest.

This dissertation explores the gas-phase catalytic HDO of AA over catalysts supported on activated carbon (Cp-97). Temperature-dependent conversion and selectivity were studied at 1 atm from 200-4000C with an AA concentration of 1.1% and 20% …


Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde Apr 2017

Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde

Electronic Theses and Dissertations

Biomass processing for industrial products and biofuels has gained an increasing presence as society looks to using sustainable resources for manufacturing and renewable fuels for energy. However, these sustainably produced materials and products cannot gain a competitive edge because of the manufacturing expenses that are a result of high process temperatures and pressures. In order to lower these costs, theoretical modeling has described a value-added co-product strategy as one of the best ways to combat high bioprocessing prices. Biomass has been shown to make effective carbons for energy storage devices such as supercapacitors and batteries. These carbons, with the right …


Silk-Derived Graphene-Like Carbon With High Electrocatalytic Activity For Oxygen Reduction Reaction, Qingfa Wang, Ruoping Yanzhang, Yaqing Wu, Han Zhu, Junfeng Zhang, Mingliang Du, Ming Zhang, Li Wang, Xiangwen Zhang, Xinhua Liang Mar 2016

Silk-Derived Graphene-Like Carbon With High Electrocatalytic Activity For Oxygen Reduction Reaction, Qingfa Wang, Ruoping Yanzhang, Yaqing Wu, Han Zhu, Junfeng Zhang, Mingliang Du, Ming Zhang, Li Wang, Xiangwen Zhang, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

A facile method to prepare the nanoporous and graphene-like carbon material from a natural silk fiber was developed by a potassium intercalation and carbonization procedure. The as-synthesized graphene-like fiber was employed for oxygen reduction reaction and exhibited impressive electrocatalytic activity.


Size-Controlled Large-Diameter And Few-Walled Carbon Nanotube Catalysts For Oxygen Reduction, Xianliang Wang, Qing Li, Hengyu Pan, Ye Lin, Yujie Ke, Haiyang Sheng, Mark T. Swihart, Gang Wu Nov 2015

Size-Controlled Large-Diameter And Few-Walled Carbon Nanotube Catalysts For Oxygen Reduction, Xianliang Wang, Qing Li, Hengyu Pan, Ye Lin, Yujie Ke, Haiyang Sheng, Mark T. Swihart, Gang Wu

Faculty Publications

We demonstrate a new strategy for tuning the size of large-diameter and few-walled nitrogen-doped carbon nanotubes (N-CNTs) from 50 to 150 nm by varying the transition metal (TM = Fe, Co, Ni or Mn) used to catalyze graphitization of dicyandiamide. Fe yielded the largest tubes, followed by Co and Ni, while Mn produced a clot-like carbon morphology. We show that morphology is correlated with electrocatalytic activity for the oxygen reduction reaction (ORR). A clear trend of Fe > Co > Ni > Mn for the ORR catalytic activity was observed, in both alkaline media and more demanding acidic media. The Fe-derived N-CNTs exhibited …


Modeling Lithium Intercalation In A Porous Carbon Electrode, Gerardine G. Botte, Ralph E. White Mar 2015

Modeling Lithium Intercalation In A Porous Carbon Electrode, Gerardine G. Botte, Ralph E. White

Ralph E. White

No abstract provided.


Estimation Of The Effect Of Catalyst Physical Characteristics On Fenton-Like Oxidation Efficiency Using Adaptive Neuro-Fuzzy Computing Technique Dec 2014

Estimation Of The Effect Of Catalyst Physical Characteristics On Fenton-Like Oxidation Efficiency Using Adaptive Neuro-Fuzzy Computing Technique

Faculty of Engineering University of Malaya

Catalyst size, which determines surface area, is one of the major factors in catalytic performance. In this study, response surface methodology (RSM) and an adaptive neuro-fuzzy inference system (ANFIS) were applied to quantify the effects of physical characteristics of magnetite on Fenton-like oxidation efficiency of methylene blue. For this purpose, two magnetite samples (M and N) were used and characterized by XRD, BET surface area, particle size analyzer and FE-SEM. Central composite design (CCD) was applied to design the experiments, develop regression models, optimize and evaluate the individual and interactive effects of five independent variables: H2O2 and catalyst concentrations, pH, …


On Electric Conduction Of Amorphous Silicon Carbonitride Derived From A Polymeric Precursor, Yaohan Chen, Fuqian Yang, Linan An Jun 2013

On Electric Conduction Of Amorphous Silicon Carbonitride Derived From A Polymeric Precursor, Yaohan Chen, Fuqian Yang, Linan An

Chemical and Materials Engineering Faculty Publications

A long-existing problem that the conductivity of amorphous silicon carbonitrides derived from polymeric precursor increases significantly with pyrolysis temperature is investigated. We show that the conductivity exhibited an Arrhenius dependence on pyrolysis temperature, with the activation energy of ∼3.41 eV. Structural analysis using Raman spectroscopy reveals that the free carbon within the material undergoes a sp3-to-sp2 transition as pyrolysis temperature increases, with the activation energy of ∼3.6 eV. We conclude that the pyrolysis-temperature induced increase in the conductivity is mainly due to the increase in the conductivity of the free carbon. A simple model is proposed to …


Improving The Adsorption Of Heavy Metals From Water Using Commercial Carbons Modified With Egg Shell Wastes, Alejandro Guijarro-Aldaco, Virginia Hernandez-Montoya, Adrian Bonilla-Petriciolet, Miguel A. Montes-Moran, Didilia I. Mendoza-Castillo Jan 2011

Improving The Adsorption Of Heavy Metals From Water Using Commercial Carbons Modified With Egg Shell Wastes, Alejandro Guijarro-Aldaco, Virginia Hernandez-Montoya, Adrian Bonilla-Petriciolet, Miguel A. Montes-Moran, Didilia I. Mendoza-Castillo

Adrian Bonilla-Petriciolet

We introduce the application of hen egg shell waste to improve the adsorption capacities of heavy-metal ions using commercial carbons via the modification of their surface chemistry. Specifically, a calcium solution extracted from egg shell waste has been used as a low-cost activation agent to improve the adsorption properties of three commercial carbons. An orthogonal array of the Taguchi method has been applied to identify the optimal conditions for the adsorbent modification process using the Zn batch adsorption, at 30 °C and pH 5, as the response variable. Our results show that maximum adsorption capacities of Cd, Ni, and Zn …


Oxygen Diffusion Characterization Of Frp Composites Used In Concrete Repair And Rehabilitation, Chandra K. Khoe Jan 2011

Oxygen Diffusion Characterization Of Frp Composites Used In Concrete Repair And Rehabilitation, Chandra K. Khoe

USF Tampa Graduate Theses and Dissertations

Many independent studies have conclusively demonstrated that fiber reinforced polymers (FRP) slow down chloride-induced corrosion of steel in concrete. The mechanism for this slow down is not well understood but it has been hypothesized that FRP serves as a barrier to the ingress of chloride, moisture, and oxygen that sustain electrochemical corrosion of steel.

This dissertation presents results from an experimental study that determined the oxygen permeation rates of materials used in infrastructure repair. In the study, the oxygen permeation constants for epoxy, carbon and glass fiber laminates, concrete, epoxy-concrete and FRP-concrete systems were determined and a method developed to …


Theoretical Analysis Of Stresses In A Lithium Ion Cell, Sindhuja Renganathan, Godfrey Sikha, Shriram Santhanagopalan, Ralph E. White Jan 2010

Theoretical Analysis Of Stresses In A Lithium Ion Cell, Sindhuja Renganathan, Godfrey Sikha, Shriram Santhanagopalan, Ralph E. White

Faculty Publications

A mathematical model to simulate the generation of mechanical stress during the discharge process in a dual porous insertion electrode cell sandwich comprised of lithium cobalt oxide and carbon is presented. The model attributes stress buildup within intercalation electrodes to two different aspects: changes in the lattice volume due to intercalation and phase transformation during the charge/discharge process. The model is used to predict the influence of cell design parameters such as thickness, porosity, and particle size of the electrodes on the magnitude of stress generation. The model developed in this study can be used to understand the mechanical degradation …


Analytical Expression For The Impedance Response For A Lithium-Ion Cell, Godfrey Sikha, Ralph E. White Jan 2008

Analytical Expression For The Impedance Response For A Lithium-Ion Cell, Godfrey Sikha, Ralph E. White

Faculty Publications

An analytical expression to predict the impedance response of a dual insertion electrode cell (insertion electrodes separated by an ionically conducting membrane) is presented. The expression accounts for the reaction kinetics and double-layer adsorption processes at the electrode-electrolyte interface, transport of electroactive species in the electrolyte phase, and insertion of species in the solid phase of the insertion electrodes. The accuracy of the analytical expression is validated by comparing the impedance response predicted by the expression to the corresponding numerical solution. The analytical expression is used to predict the impedance response of a lithium-ion cell consisting of a porous LiCoO …


Development Of Method For Synthesis Of Pt–Co Cathode Catalysts For Pem Fuel Cells, Xuguang Li, Héctor R. Colón-Mercado, Gang Wu, Jong-Won Lee, Branko N. Popov Jan 2007

Development Of Method For Synthesis Of Pt–Co Cathode Catalysts For Pem Fuel Cells, Xuguang Li, Héctor R. Colón-Mercado, Gang Wu, Jong-Won Lee, Branko N. Popov

Faculty Publications

A procedure was developed to synthesize a platinum–cobalt (Pt–Co) alloy electrocatalyst for oxygen reduction using Co/C composite as a support. The Pt–Co/C catalysts were synthesized through: (i) chemical oxidation of carbon black, (ii) Co deposition on the oxidized carbon using a chelation method, (iii) chemical treatment in an acidic medium to remove excess of Co on the carbon surface, (iv) Pt deposition onto the Co/C support, and (v) postheat treatment to form the Pt–Co alloy catalyst. The synthesized Pt–Co/C catalyst showed improved activity and long-term stability in polymer electrolyte membrane …


Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin Aug 2005

Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin

Istadi

This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane …


Catalytic Conversion Of Hydrocarbons To Hydrogen And High-Value Carbon, Naresh Shah, Devadas Panjala, Gerald P. Huffman Apr 2005

Catalytic Conversion Of Hydrocarbons To Hydrogen And High-Value Carbon, Naresh Shah, Devadas Panjala, Gerald P. Huffman

Chemical and Materials Engineering Faculty Patents

The present invention provides novel catalysts for accomplishing catalytic decomposition of undiluted light hydrocarbons to a hydrogen product, and methods for preparing such catalysts. In one aspect, a method is provided for preparing a catalyst by admixing an aqueous solution of an iron salt, at least one additional catalyst metal salt, and a suitable oxide substrate support, and precipitating metal oxyhydroxides onto the substrate support. An incipient wetness method, comprising addition of aqueous solutions of metal salts to a dry oxide substrate support, extruding the resulting paste to pellet form, and calcining the pellets in air is also discloses. In …


Development And Model Formulation Of Scalable Carbon Nanotube Processes: Hipco And Comocat Process Models, Adedeji Ebenezer Agboola Jan 2005

Development And Model Formulation Of Scalable Carbon Nanotube Processes: Hipco And Comocat Process Models, Adedeji Ebenezer Agboola

LSU Master's Theses

Carbon nanotubes are seamless cylindrical tubes, consisting of carbon atoms arranged in a regular hexagonal structure. It is considered as the ultimate engineering material because of its unique and distinct electronic, mechanical and material characteristics. The discovery of these materials pioneered the nanotechnology revolution, which encompasses a broad and multidisciplinary spectrum, including nanomaterials, nanobiotechnology, and nanoelectronics. Hundreds of published articles of laboratory scale and pilot plant processes were reviewed that describe potential synthesis and post–synthesis purification methods for large scale production of carbon nanotubes. The main production technologies include electric arc discharge, laser vaporization, and catalytic chemical vapor deposition. These …


Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov Jan 2004

Development Of Novel Method For Preparation Of Pemfc Electrodes, Hansung Kim, Branko N. Popov

Faculty Publications

A method based on pulse electrodeposition technique was developed for preparation of membrane electrode assemblies (MEAs). In this approach, platinum is deposited directly on the surface of the carbon electrode. The method ensures most of the platinum to be in close contact with the membrane. Using this method it is possible to increase the Pt/C ratio up to 75 wt % near the surface of the electrode resulting in a 5 µm thick catalyst layer. The MEA prepared by pulse electrodeposition exhibits a current density of 0.33 A/cm2 at 0.8 V with platinum loading of 0.25 mg of Pt/cm …


Modeling Of Cane Sugar Colorant Removal In Packed-Bed Ion Exchange Columns And An Investigation Into Pretreatment Methods, Bruce Malcolm Ellis Jan 2004

Modeling Of Cane Sugar Colorant Removal In Packed-Bed Ion Exchange Columns And An Investigation Into Pretreatment Methods, Bruce Malcolm Ellis

LSU Master's Theses

Cane sugar colorants have been extensively researched but still little is known about their exact compositions. Rather than distinct compounds, they are a mixture of many compounds. Some it is assumed can be classified into the pseudo components that have been defined using gel permeation chromatography, based on molecular weight. The defining of these components has allowed the colorants to be modeled independently, instead of as one lumped color parameter. The measured colored components were modeled using a linear driving force adsorption model, which could be applied in the design process for optimizing the decolorizing capacity of the resins. The …


A Mathematical Model Of Oxide/Carbon Composite Electrode For Supercapacitors, Hansung Kim, Branko N. Popov Jan 2003

A Mathematical Model Of Oxide/Carbon Composite Electrode For Supercapacitors, Hansung Kim, Branko N. Popov

Faculty Publications

A pseudo two-dimensional model is developed for the general application of supercapacitors consisting of an oxide/carbon composite electrode. The model takes into account the diffusion of protons in the oxide particle by employing the method of superposition. RuO2/carbon system is modeled as a specific example. From the simulation data, it is found that the oxide particle size and proton diffusion coefficient have an enormous effect on the performance at high discharge rate due to the limitation of proton transport into RuO2 particles. With increasing carbon ratio, the porosity of electrode increases, which causes the potential drop in …


Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn Jan 2002

Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn

Faculty Publications

This work presents a mathematical model for charge/discharge of electrochemical capacitors that explicitly accounts for particle-packing effects in a composite electrochemical capacitor consisting of hydrous RuO2 nanoparticles dispersed within porous activated carbon. The model is also used to investigate the effect of nonuniform distributions of salt in the electrolyte phase of the electrode in the context of dilute solution theory. We use the model to compare the performance of capacitors with electrodes made from different activated carbons and to investigate the effects of varying carbon content and discharge current density. Even at low discharge current density, concentration polarization in …


Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn Jan 2002

Modeling The Effects Of Electrode Composition And Pore Structure On The Performance Of Electrochemical Capacitors, Changqing Lin, Branko N. Popov, Harry J. Ploehn

Faculty Publications

This work presents a mathematical model for charge/discharge of electrochemical capacitors that explicitly accounts for particle-packing effects in a composite electrochemical capacitor consisting of hydrous RuO2 nanoparticles dispersed within porous activated carbon. The model is also used to investigate the effect of nonuniform distributions of salt in the electrolyte phase of the electrode in the context of dilute solution theory. We use the model to compare the performance of capacitors with electrodes made from different activated carbons and to investigate the effects of varying carbon content and discharge current density. Even at low discharge current density, concentration polarization in …