Engineering Science and Materials Commons^™

The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen

Journal of Electrochemistry

The deoxidation speed of a solid oxide cathode in molten CaCl₂ can be estimated by the PRS steady diffusion model of O^2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta₂O₅, the porosity of the cathode is better to be within 50%. …

23Na Mas Nmr Spectroscopic Study Of Na2Mnpo4F As Cathode Material For Sodium-Ion Battery, Xu Hou, Gui-Ming Zhong, Xiao-Chen Lin, Zi-Geng Liu, Xiao-Biao Wu, Yong Yang

Journal of Electrochemistry

The Na₂MnPO₄F is one of the promising cathode materials for the sodium ion batteries. In the paper, we employed the ex situ X-ray diffraction and solid state NMR techniques to study the charge and discharge processes of this material, including the crystal structure and sodium sites changes. The ex situ x-ray diffraction patterns showed that two new diffraction peaks could be observed at 31^o and 36^o indicating an intermediate phase formed with the extraction of Na⁺. From the ²³Na MAS NMR spectrum of the material, three peaks were seen at -209 …

Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O₂ and the serial protonation process of dissociated products to form H₂O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …

Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The CoFe₂O₄/GNS was synthesized by a simple one-pot solvothermal method. The results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the CoFe₂O₄ particles with sizes of 15 nm dispersed on the surface of graphene uniformly. Electrochemical tests indicated that the CoFe₂O₄/GNS nanocomposite exhibited excellent cyclic stability with almost 95.8% capacity retention after 100 cycles at the current density of 500 mA·g^-1 and delivered a high reversible capacity of 482 mAh·g^-1 at the current density of 2 A·g^-1.

Electro-Catalytic Oxidation Of Hydrogen Peroxide On Au/ L-Methionine /Gc Electrode, Jian-Feng Fan, Xue-Mei Luo, Jing Li, Lou-Zhen Fan

Journal of Electrochemistry

The modified electrodes have been fabricated by generation of Au nanoparticle chains, which was produced by reaction between HAuCl4 and sodium citrate without any additional capping agents or surfactants. The self-assembled Au nanoparticles were attached to the surface of glassy carbon electrode (GCE) layer by layer, using L-methionine (L-Met), thiourea (TU), allyl thiourea (ATU) and polyvinylpyrrolidone (PVP) as a crosslinking agent, respectively. The experimental results showed that the electrochemical performance of the different modified electrodes varied in [Fe(CN)₆]^3-/4- solution. The Au/L-Met/GCE exhibited an excellent electrochemical property, which is superior to other modified electrodes. In addition, the catalysis …

Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao

Journal of Electrochemistry

Platinum nanocrystallites were synthesized by the colloidal method using oxamide as the stabilizer. The morphologies and electrocatalytic performances for methanol of platinum nanocrystallites prepared at different pH values and with different reactant ratios of precursor and stabilizer were investigated. It was found that the platinum nanocrystallites synthesized at pH=5 and with the reactant ratio of 1:20 showed the best electrocatalytic activity for methanol. The peak current density reached up to 1709 μA·cm^-2. Furthermore, the electrocatalytic activity of platinum nanocrystallites for methanol reduced significantly although the cyclic voltammograms in the blank solution were not obviously changed after exposing in …

Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu

Journal of Electrochemistry

Three kinds of conductive carbon films were prepared with Super-P (SP), KB and MWCNTs, and then the as-prepared carbon films were applied as an interlayer between a sulfur electrode and a separator for constructing a coin-type lithium-sulfur (Li-S) cell, respectively. The assessment results show that all the cells delivered the reversible capacities higher than 800 mAh·g^-1 after 40 cycles when the sulfur loading was up to 80% (by mass) in the sulfur electrode. Due to significant differences of physical properties among the carbon materials, the cell with a KB interlayer exhibited higher electrochemical polarization; the cycling performance of the …

Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun

Journal of Electrochemistry

White TiO₂ nanorods were synthesized by hydrothermal method with TiCl₄ as a precursor. As-synthesized TiO₂ nanorods were further subjected to high-temperature (550 ^oC) heat treatment for 2 h under H₂ atmosphere to prepare gray black hydrogen-treated TiO₂ (H-TiO₂) nanorods with oxygen vacancies and Ti³⁺ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO₂ nanorods to form Pt/TiO₂ and Pt/H-TiO₂ catalysts. XRD data indicates that the crystal structure of TiO₂ was still reserved as rutile after hydrogen treatment, but the surface …

Effect Of Al-Doping In Li-Rich Material Li1.2Mn0.543Co0.078Ni0.155Al0.030O2 For Lithium-Ion Batteries, Xiao-Xi Jin, Yi-Xiao Li, Yong Yang, Zhou-Cheng Wang

Journal of Electrochemistry

The Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni_0.4)O₂ compounds were successfully synthesized as cathode materials for lithium-ion batteries. The pristine and Al-doped materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and laser Raman spectroscopy. The results indicated that all the prepared materials were indexed as a hexagonal structure with R-3m space group, and Al element had been introduced into lattice. When cycled at 180 mA·g^-1 (1 C-rate), the capacity retention of 4% (by mole) Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni …

Application Of Ionic Liquid Pp14Tfsi In Electrolyte Systems For Rechargeable Mg Batteries, Jin-Jie Zhu, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Yan-Na Nuli, Jiu-Lin Wang

Journal of Electrochemistry

A phenolated-based Mg salt was prepared. The mixture of THF and N-methyl-N-butyl-piperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) serves as the mixed solvent instead of pure THF for rechargeable Mg batteries systems. This new type of electrolyte system not only has optimal reversibility of Mg, but also owns a wide electrochemical window (2.7 V vs. Mg) and high ionic conductivity (7.77 mS·cm^-1). More importantly, the addition of Ionic Liquid suppresses the volatility of THF and improves the safety of rechargeable Mg batteries. The result shows that the mixture of THF and piperidyl-based Ionic Liquid could be regarded as a good solvent candidate …

Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang

Journal of Electrochemistry

A platinum electrode decorated with the ordered Nd-Fe-MoO₄^2- cyano-bridged mixed coordination polymer was successfully prepared by electrodeposition in virtue of the lyotropic liquid crystal soft template methods, and electrocatalytic oxidation behavior of glycerol was investigated on the chemically modified electrode by cyclic voltammetry. The influences of experimental factors such as the concentrations of H⁺ and SO₄^2- in electrolytes, glycerol concentration and scan rate on the electrocatalytic activity of glycerol at the modified electrode were also studied. It indicated that the proper amount of SO₄^2- in weakly acidic electrolyte could help to improve the …

Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie

Journal of Electrochemistry

Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.

An Equivalent Circuit Model For Redox Flow Battery Stack, Dong-Jiang You, Hua-Min Zhang

Journal of Electrochemistry

This paper introduces an equivalent circuit model for a redox flow battery stack. The model combines the electrochemical reaction of the battery cell and the shunt current of the battery stack. An all-vanadium redox flow battery stack of 1kW rated output power is tested through transient response and self-discharge experiments. All the parameters used for the modeling are obtained. Calculated shunt current and distribution of calculated battery voltage are shown in the results. It is concluded that the impedance of the battery stack can be obtained by the experimental results of the transient response and self-discharge measurements. The capacity lose …

Electrochemical Performance Of Si-C Composites Prepared By Discharge-Plasma Assisted Milling, Yu-Long Chen, Ren-Zong Hu, Hui Liu, Wei Sun, Min Zhu

Journal of Electrochemistry

Silicon-carbon (Si-C) composites, with microstructure of multi-scaled Si particles being homogenously dispersed in micro-sized carbon matrix, had been prepared by dielectric barrier discharge plasma assisted two-step milling for the first time. The Si-C composite anode had a discharge capacity of 1259 mAh·g^-1 at the first cycle, while the capacity retained 474 and 396 mAh·g^-1 after 20 and 100 cycles, respectively. Charge-discharge curves and AC impedance response indicated that both silicon and carbon phases in the composite anode were involved during the lithiation/delithiation reactions and the electron transport resistance in the Si-C composite anode was much lower than that …

Preparation Of High Performance Porous Silicon Powders By Etching Al-Si Alloy In Acid Solution For Lithium Ion Battery, Shi-Ji Hao, Chun-Li Li, Kai Zhu, Ping Zhang, Zhi-Yu Jiang

Journal of Electrochemistry

Porous silicon powders prepared by etching Al-Si alloy using an acid solution was reported in the first time. The morphology and structure of as-obtained material were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD) method. It was found that the spongy porous silicon powders presented well crystalline structure and consisted of nano-Si particles. The particle size of porous Si powders was about 20 μm, and the specific surface area was 102.7 m²·g^-1. The electrochemical properties of porous silicon powders were evaluated as an anode material for lithium ion batteries. The material proportion in the …

Pulse Electrodeposition Of Pd-Ni Alloy Nanoparticles For Electrocatalytic Oxidation Of Formic Acid, Fang-Zu Yang, Jun-Pei Yue, Zhong-Qun Tian, Shao-Min Zhou

Journal of Electrochemistry

The Pd-Ni alloy nanoparticles with nickel atomic contents of 12.0%, 16.4% and 22.6% were successfully electrodeposited from a Pd-Ni alloy electrolyte by square wave pulse plating. The alloy nanoparticles were in the spherical shape with a diameter of 50 ~ 80 nm. As the growth potential of the alloy was negatively shifted, the nickel content of the alloy was increased, and the size of the nanoparticles was almost the same, whereas the number, the degree of crosslinking and the real active area of the nanoparticles were increased. As the nickel content of the alloy nanoparticles increased, the peak current for …

Synthesis And Electrochemical Properties Of Lico1-XMgXMno4 And Lico1-XAlXMno4 (X= 0, 0.02, 0.05, 0.1) As Positive Materials For Lithium-Ion Batteries, Mei-Ling You, Qing-Song Tong, Xiu-Hua Li, Min Lin, Xing-Kang Huang, Yong Yang

Journal of Electrochemistry

The Al-doped and Mg-doped LiCoMnO₄ materials were synthesized through solid-state reaction. The effects of doping amounts of Mg and Al on the initial capacities, discharge plateaus, and cycle performances were investigated. The morphologies and structures of the as-prepared materials were studied by scanning electron microscopy and powder X-ray diffraction. The results indicate that the as-prepared samples were composed of uniform, well-crystallized particles. The pristine LiCoMnO₄ possessed an initial capacity of 87.0 mAh·g^-1, while LiCo_0.98Mg_0.02MnO₄ and LiCo_0.98Al_0.02MnO₄ delivered 91.3 and 93.6 mAh·g^-1, respectively. The proper …

Fabrication And Impedance Performance Of Gradient Lani0.6Fe0.4O3-δ-Gd0.2Ce0.8O2 Composite Cathodes For Intermediate Temperature Solid Oxide Fuel Cell, Yang Li, Bo Huang, Meng Yuan, Zhi-Qiu Zhang, Zong-Yao Liu, Xu-Chen Tang, Xin-Jian Zhu

Journal of Electrochemistry

A LNF-GDC composite cathode with a gradual change in the composition between ScSZ electrolyte and LNF cathode was fabricated to reduce the cathode polarization resistance (R_p). The gradual change in composition between ScSZ electrolyte and LNF cathode shows the decreases in the charge transfer resistance (R_ct) and gas phase diffusion resistance (R_d). The results revealed that the Rp value, measuring 0.452 Ω·cm² at 750 °C, was the lowest for LNF-GDC composite cathodes with three layers and gradient changes in composition between ScSZ and LNF (Cathode C),, whereas the Rp value of 70%LNF-30%GDC composite …

Electrochemical Oxidation Of Ammonium Nitrite In Absorption Solution Of Flue Gas, Yong-Hong Lu, Xiao-Bo Dong, Li-Sha Wang, Yan Liu, Chen-Jian Zhu, Hai-Bo Xu

Journal of Electrochemistry

In order to make full uses of ammonium nitrite in absorption solution from flue gas simultaneous desulfurization, denitrification and demercurization processes, here the electrochemical oxidation method was used to transform ammonium nitrite into ammonium nitrate. By using polarization curve, cyclic voltammogram and galvanostatic methods, suitable electrode materials were evaluated and chosen. The influence of electrolyte composition was discussed and the appropriate process parameters were obtained. Finally, the effect of electrochemical oxidation was confirmed by chemical analysis method. In 0.05 mol·L^-1 NaNO₂ + 0.05 mol·L^-1 (NH₄)₂SO₄ simulated absorption solution (5 L, pH = …

Study On Carbon Supported Pd Catalysts Modified By Phosphomolybdic Acid For H2O2 Electrocatalytic Reduction, Li-Mei Sun, Cheng Zhang, Ying-Rong Bao, Hong-Xia Li

Journal of Electrochemistry

The Pd/C catalyst was prepared with the chemical reduction method, and phosphomolybdic acid (PMA) was modified on the Pd/C catalyst using the dipping method. The compositions and structures of the Pd/C and Pd/C modified by phosphomolybdic acid (PMA-Pd/C) catalysts were characterized with X-ray diffraction and Fourier Transform infrared spectroscopy analyses. The electrocatalytic activity and stability of the catalysts for the reduction of hydrogen peroxide (H₂O₂) were studied using cyclic voltammetry and chronoamperometry. The results showed that the phosphomolybdic acid was tightly fixed on the surface of Pd/C catalyst through the chemical interaction. The eletrocatalytic activity of …

Preparation Of Pd/Tio2/C Catalyst And Its Electrocatalytic Performance In Basic Solution For Ethanol Oxidation, Qiao-Xia Li, Yi-Chao Yang, Ming-Shuang Liu, Hong-Min Mao, Qun-Jie Xu

Journal of Electrochemistry

Nanoparticles TiO₂ were prepared by hydrothermal method using precursor tetrabutyl titanate. The Pd/TiO₂/C catalyst was synthesized by liquid phase reducing method supported on nano TiO₂ and Vulcan carbon XC-72. The Pd/TiO₂/C catalyst was characterized by XRD, TEM, cyclic voltammetry, and chronopotentiometry. XRD confirmed the face-centered cubic structure of Pd particles, and TEM indicated that Pd particles (size 3 ~ 4 nm) dispersed uniformly on TiO₂ and carbon XC-72. The results from cyclic voltammogram and chronopotentiogram showed the higher ethanol oxidation activity and stability of Pd/TiO₂/C catalyst (20% Pd) as compared with …

Design And Development Of A Novel Glucose Biosensor Based On The Ferrocene-Functionalized Fe3O4 Nanoparticles/Carbon Nanotubes/Chitosan Nanocomposite Film Modified Electrode, Hua-Ping Peng, Dai-Jun Zha, Wei Chen, Ai-Lin Liu, Xin-Hua Lin

Journal of Electrochemistry

A novel platform for the fabrication of glucose biosensor was successfully constructed by entrapping glucose oxidase (GOD) in a ferrocene monocarboxylic acid-aminated Fe₃O₄ magnetic nanoparticles conjugate (FMC-AFNPs)/chitosan (CS)/multiwall carbon nanotubes (MWNTs) nanocomposite. The formation of FMC-AFNPs could effectively prevent the leakage of ferrocene and retain its electrochemical activity. This GOD/FMC-AFNPs/CS/MWNTs matrix provided a biocompatible microenvironment for retaining the native activity of the immobilized GOD. Moreover, the presence of MWNTs enhanced the charge-transport properties of the composite and facilitated electron transfer between the GOD and the electrode for the electrocatalysis of glucose. Under the optimal conditions the designed …

Introduction To Special Issue Of Journal Of Defense Modeling And Simulation: Novel Approaches To Defense And Military Modeling And Simulation, Scott D. Snyder, James M. Taylor Jr.

Peter Kiewit Institute: Faculty Publications

Developing solutions to complex problems in government and industry is a daunting task that often requires tremendous investment in time and resources to solve. Modeling and simulation (M&S) has incredible potential to streamline development and cut costs by conducting virtual experiments that give insight into performance under various test conditions. As many program managers in the federal acquisition process can attest, realistic testing of live equipment in an operational environment can be some of the most expensive parts of a development program. M&S can provide insight into mission success of yetto- bedesigned systems without the need to actually build and …

Simple Multi-Attribute Rating Technique For Renewable Energy Deployment Decisions (Smart Redd), James M. Taylor Jr., Betty Love

Peter Kiewit Institute: Faculty Publications

In the effort to provide electrical power service and the sustaining fuel required to run generators at forward-deployed bases in Afghanistan and Iraq over more than 10 years, the United States military spent billions of dollars and a paid a heavy toll in terms of human casualties. The green energy linear program for optimizing deployments (GELPOD) proof-of-concept model showed that a linear program could be used to optimize combat deployment of energy generation systems to minimize cost and casualties. Results indicated that reduction in both cost and casualties for renewable energy sources was highly dependent on fuel cost and deployment …

Applying Spiking Neural Network Simulation To Neuromodulatory Autonomous Robot Control, Cameron Muhammad

Phi Kappa Phi Research Symposium (Archived)

In this paper, simulation of the brain based on an artificial spiking neuron model is used to create a self-learning algorithm. The spiking neuron simulation is used to demonstrate a neuromodulation program in which the reward seeking properties of dopamine, the risk-adverse effects of serotonin, and the attention-focusing effects of the cholinergic and noradrenergic systems are applied to a mobile robotic platform as it moves autonomously throughout an environment. External stimuli is recorded by the program as spiking “events” that result in corresponding amounts of dopamine and serotonin influenced spiking patterns. These spiking patterns affect how the robot adapts to …

3d Printed Electromagnetic Transmission And Electronic Structures Fabricated On A Single Platform Using Advanced Process Integration Techniques, Paul I. Deffenbaugh

Open Access Theses & Dissertations

3D printing has garnered immense attention from many fields including in-office rapid prototyping of mechanical parts, outer-space satellite replication, garage functional firearm manufacture, and NASA rocket engine component fabrication. 3D printing allows increased design flexibility in the fabrication of electronics, microwave circuits and wireless antennas and has reached a level of maturity which allows functional parts to be printed. Much more work is necessary in order to perfect the processes of 3D printed electronics especially in the area of automation. Chapter 1 shows several finished prototypes of 3D printed electronics as well as newly developed techniques in fabrication. Little is …

Growth And Analysis Of Micro And Nano Cdte Arrays For Solar Cell Applications, Brandon Adrian Aguirre

Open Access Theses & Dissertations

CdTe is an excellent material for infrared detectors and photovoltaic applications. The efficiency of CdTe/CdS solar cells has increased very rapidly in the last 3 years to ~20% but is still below the maximum theoretical value of 30%. Although the short-circuit current density is close to its maximum of 30 mA/cm2, the open circuit voltage has potential to be increased further to over 1 Volt. The main limitation that prevents further increase in the open-circuit voltage and therefore efficiency is the high defect density in the CdTe absorber layer. Reducing the defect density will increase the open-circuit voltage above 1 …

Design Of Three Different Particle Size Distributions In Silver Paste Through Computer Simulation For Higher Electrical Conductivity, Kyungdeok Jang

Open Access Theses & Dissertations

In the field of printed electronics technology, researchers have tried to print highly conductive electrodes with fine width and height in order to manufacture high performance devices.

The purpose of this research is to print particle monolayer silver patterns which have better electrical conductivity than existing ones. The key idea of this experiment is to analyze silver inks with different sized particles. Let us consider a particle monolayer pattern printed with silver ink consisting of mono-sized particles. Inside of the pattern, there are some vacant spaces between the particles, which can lead to low electrical conductivity and discontinuity of the …

Application Of Synchrotron Radiation Based Electrochemical In-Situ Techniques To Study Of Electrode Materials For Lithium-Ion Batteries, Zheng-Liang Gong, Wei Zhang, Dong-Ping Lv, Xiao-Gang Hao, Wen Wen, Zheng Jiang, Yong Yang

Journal of Electrochemistry

Due to its merits of high brightness and high intensity, high level of polarization and wide tunability in energy, etc., synchrotron radiation technique provides an unique platform for analysis of the relationship among composition–structure–performance of materials for lithium ion batteries, especially for in-situ, real time dynamic investigation of the electrochemical reaction mechanism, aging process and failure mechanism during charge-discharge cycling. In this paper, we review the latest developments in application of synchrotron based electrochemical in-situ experimental methods to studies of lithium ion batteries. The paper mainly focuses on the application of electrochemical in-siu XRD and XAFS techniques to the investigations …

Controllable Synthesis Of Dispersed Spherical Fe3O4 Nanoparticles As Lithium-Inserted Materials, Hong-Li Zou, Wei-Shan Li

Journal of Electrochemistry

Dispersed spherical Fe₃O₄ nanoparticles were synthesized by a hydrothermal method. The influences of odecyl trimethyl ammonium bromide (DTAB) concentration on the morphology and particle size of the as-prepared Fe₃O₄ were studied. Electrochemical performance of the as-prepared sample as anode materials of lithium ion battery was investigated. It is found that the as-prepared sample exhibits superior rate performance and cycle performance. The nano-sized materials provide structural stability and favor the transfer of lithium ions.