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Articles 2611 - 2640 of 3921

Full-Text Articles in Power and Energy

Electrochemical Na-Storage Materials And Their Applications For Na-Ion Batteries, Jiang-Feng Qian, Xue-Ping Gao, Han-Xi Yang Dec 2013

Electrochemical Na-Storage Materials And Their Applications For Na-Ion Batteries, Jiang-Feng Qian, Xue-Ping Gao, Han-Xi Yang

Journal of Electrochemistry

Oncoming large scale electric energy storage (EES) requires battery systems not only to have sufficient storage capacity but also to be cost-effective and environmentally friendly. Li-ion batteries for widespread EES applications may be limited due to the constraint of global lithium resource. From the considerations of available resources and environmental impact, Na-ion batteries have potential advantages as next generation secondary batteries and an alternative to Li-ion batteries. However, in the present state of the art, the Na-storage cathodes reported so far are still deficient both in energy density and power capability, while the carbon and alloy anodes for Na-ion batteries …


Surface Composition Structure And Electrochemical Performance Of Aluminum Doped Lifepo4, Huai-Fang Shang, Wei-Feng Huang, Wang-Sheng Hu, Ding-Guo Xia, Zi-Yu Wu Dec 2013

Surface Composition Structure And Electrochemical Performance Of Aluminum Doped Lifepo4, Huai-Fang Shang, Wei-Feng Huang, Wang-Sheng Hu, Ding-Guo Xia, Zi-Yu Wu

Journal of Electrochemistry

Despite there are many successful reports about the preparation of electrode materials with surface coating for lithium ion batteries, the study in surface self-coating of cathode materials using segregation of doping elements and their electrochemical properties is still very rare. The LiFePO4 particles with rich-Al on the surface were synthesized by one step solvothermal route. TEM results demonstrated that the surface of the obtained LiFePO4 particles was well-covered by the amorphous coating. The soft X-ray absorption spectroscopy (XAS) and Auger electron spectroscopy (AES) component analyses revealed that the amorphous coating was composed of LiFe1-xAlxPO …


Predicting Voltage Abnormality Using Power System Dynamics, Nagendrakumar Beeravolu Dec 2013

Predicting Voltage Abnormality Using Power System Dynamics, Nagendrakumar Beeravolu

LSU New Orleans Theses and Dissertations

The purpose of this dissertation is to analyze dynamic behavior of a stressed power system and to correlate the dynamic responses to a near future system voltage abnormality. It is postulated that the dynamic response of a stressed power system in a short period of time-in seconds-contains sufficient information that will allow prediction of voltage abnormality in future time-in minutes. The PSSE dynamics simulator is used to study the dynamics of the IEEE 39 Bus equivalent test system. To correlate dynamic behavior to system voltage abnormality, this research utilizes two different pattern recognition methods one being algorithmic method known as …


Battery Energy Storage Systems To Mitigate The Variability Of Photovoltaic Power Generation, Heath Alan Gurganus Dec 2013

Battery Energy Storage Systems To Mitigate The Variability Of Photovoltaic Power Generation, Heath Alan Gurganus

Dissertations and Theses

Methods of generating renewable energy such as through solar photovoltaic (PV) cells and wind turbines offer great promise in terms of a reduced carbon footprint and overall impact on the environment. However, these methods also share the attribute of being highly stochastic, meaning they are variable in such a way that is difficult to forecast with sufficient accuracy. While solar power currently constitutes a small amount of generating potential in most regions, the cost of photovoltaics continues to decline and a trend has emerged to build larger PV plants than was once feasible. This has brought the matter of increased …


Motor Protection Lab Experiment Using Sel-710, Ozro Corulli Dec 2013

Motor Protection Lab Experiment Using Sel-710, Ozro Corulli

Electrical Engineering

Advancements in microprocessor based relay technology for power protection applications provide quicker response times and new methods of mitigation. This project develops a lab experiment for Cal Poly class EE444 - Power Systems Laboratory based on the Schweitzer SEL-710 motor protection relay. Learning objectives for this lab include relay setup, programming, and protection schemes for the following conditions: undervoltage, loss of phase, fault, locked rotor, and thermal overload. Today, utility companies across the globe use SEL relays for primary system protection, putting engineers familiar with their operation in high demand.


Adjust Decision-Making Targets Based On Psychological Thresholds, Jian Liu, Shun Xiang Wu, Si Feng Liu, Qiao Wang Dec 2013

Adjust Decision-Making Targets Based On Psychological Thresholds, Jian Liu, Shun Xiang Wu, Si Feng Liu, Qiao Wang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper study the impact of psychological thresholds (PTs) on the decision maker's (DM's) decision target when making decision. A new approach of decision making is proposed in this paper. First, we construct criterion expected functions according to three different types of criteria: profit type, cost-type and intermediate-type, respectively. Then, we calculate the local degree of satisfaction (LDS) of each object when PTs exists, in order to adjust the initial decision target to make up new decision table. Later, by weighting the criteria reaching the DM's degree of satisfaction (DS) along with information aggregation algorithm, we obtain the overall satisfaction …


Fea Estimation And Experimental Validation Of Solid Rotor And Magnet Eddy Current Loss In Single-Sided Axial Flux Permanent Magnet Machines, Xu Yang Dec 2013

Fea Estimation And Experimental Validation Of Solid Rotor And Magnet Eddy Current Loss In Single-Sided Axial Flux Permanent Magnet Machines, Xu Yang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

The rotor and magnet loss in single-sided axial ux permanent magnet (AFPM) machines with non-overlapped windings is studied in this dissertation. Finite element analysis (FEA) estimations of the loss are carried out using both 2D and 3D modeling. The rotor and magnet losses are determined separately for stator slot passing and MMF space harmonics from currents in the stator. The segregation of loss between the solid rotor plate and the magnet is addressed. The eddy current loss reduction by magnet segmentation is discussed as well. Two prototype 24 slot/22 pole single-sided AFPMs, fabricated with both single layer (SL) and double …


Portable Nano-Hydro Power Generator For The Dc House Project, Andrew Aw, James Biggs Dec 2013

Portable Nano-Hydro Power Generator For The Dc House Project, Andrew Aw, James Biggs

Electrical Engineering

This senior project report explains the construction and design of a small, portable water generator that converts kinetic energy flowing in small creeks to electrical energy as a renewable source of energy for the DC House. The DC House, in short, is a project to build a self-sustainable house for Third World countries that utilizes only DC electricity. The system consists of two converters and a charge controller for a 12V lead-acid battery. The first converter converts the hydro generator voltage output to 15 Volts for safe and proper charging of the lead-acid battery by the charge controller. The second …


Design, Fabrication And Characterization Of Plasmonic Fishnet Structures For The Enhancement Of Absorption In Thin Film Solar Cells, Sayan Seal Dec 2013

Design, Fabrication And Characterization Of Plasmonic Fishnet Structures For The Enhancement Of Absorption In Thin Film Solar Cells, Sayan Seal

Graduate Theses and Dissertations

Incorporating plasmonic structures into the back spacer layer of thin film solar cells (TFSCs) is an efficient way to improve their performance. The fishnet structure; which is a tunable, plasmonic light scatterer is used to enhance light absorption. Unlike other plasmonic particles that have been previously suggested, the fishnet is an electrically connected wire mesh and does not result in electric field localization, hence it results in greater absorption in the intrinsic Si layer. Unlike other designs, the fishnet structure is placed in the back spacer layer of the TFSC, so it does not block any incident light. There is …


Synthesis Of Pani/Nihcf Nanocomposite Particles And Eqcm Measurement Of Ion Exchange Properties In Solutions Containing Cd2+, Yu-Jiao Yang, Xiao-Gang Hao, Xu-Li Ma, Zhong-De Wang, Zhong-Lin Zhang, Nian-Chen Han Oct 2013

Synthesis Of Pani/Nihcf Nanocomposite Particles And Eqcm Measurement Of Ion Exchange Properties In Solutions Containing Cd2+, Yu-Jiao Yang, Xiao-Gang Hao, Xu-Li Ma, Zhong-De Wang, Zhong-Lin Zhang, Nian-Chen Han

Journal of Electrochemistry

The PANI/NiHCF nanocomposite particles were synthesized on the CNTs-modified Pt substrate by one-step co-polymerization using cyclic voltammetry. Electrochemical quartz crystal microbalance (EQCM) technique was adopted to investigate the polymerization process of the nanocomposite particles and the mechanism of ion exchange in aqueous solution containing Cd2+. The morphology and structure of the as-prepared composite particles were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and Fourier transform infrared spectroscopy (FT-IR). Combined with cyclic voltammetry (CV) and energy dispersive spectroscopy (EDS), the electrochemical behavior and the mechanism of ion exchange were also investigated in electrolytes of Cd2+ …


A Comparative Study In Pretreatments Of Acid Chemical Wastewater By Electrochemical Oxidation And Ozonation, Han-Shui Liu, Su Yu, Shao-Ping Tong, Chun-An Ma Oct 2013

A Comparative Study In Pretreatments Of Acid Chemical Wastewater By Electrochemical Oxidation And Ozonation, Han-Shui Liu, Su Yu, Shao-Ping Tong, Chun-An Ma

Journal of Electrochemistry

Under the condition of keeping certain acidity, the pretreatment efficiency of an acid chemical wastewater (pH 0.85) by electrochemical oxidation was compared with that by ozonation. The results showed that the electrochemical oxidation pretreatment could obtain a better result than the ozonation at pH 0.85. After the addition of 2 g·L-1 NaCl and with the electrochemical oxidation pretreatment at 30 mA·cm-2, the removal rate of chemical oxygen demand (CODCr) reached 43.4%, and the value of biochemical oxygen demand/chemical oxygen demand (BOD5/CODCr) also increased from 0.034 to 0.14 in 20 minutes, indicating significantly improvement …


Preparation Of Benzoquinone From Phenol By Electrooxidation, Dong-Fang Niu, Cheng-Kai Yu, Xin-Sheng Zhang Oct 2013

Preparation Of Benzoquinone From Phenol By Electrooxidation, Dong-Fang Niu, Cheng-Kai Yu, Xin-Sheng Zhang

Journal of Electrochemistry

The benzoquinone was prepared from phenol by electrooxidation in an H-type cell with cation exchange membrane, in which lead plates were used both as an anode and a cathode, while H2SO4 was used as a supporting electrolyte. The effects of current density, concentration of sulphuric acid, concentrations of benzoquinone in electrolyte and extractant on the yields and efficiencies of electrolysis were investigated. Under the optimized conditions of current density being 4 A·dm-2, concentration of sulphuric acid 1 mol·L-1, passed charge 3.2 A·h, the yield and current efficiency of benzoquinone could reach 68% and …


Experimental Design Methodology Applied To The Oxidation Of Quinolines In Aqueous Medium By Electro-Fenton Process, Souhaila Trabelsi Souissi, Nihal Oturan, Nizar Bellakhal, Mehmet A. Oturan Oct 2013

Experimental Design Methodology Applied To The Oxidation Of Quinolines In Aqueous Medium By Electro-Fenton Process, Souhaila Trabelsi Souissi, Nihal Oturan, Nizar Bellakhal, Mehmet A. Oturan

Journal of Electrochemistry

The degradation behavior of 8-hydroxyquinoleine sulfate (8-HQS), a model molecule of quinolines, was studied in an aqueous medium by electro-Fenton process using a carbon felt cathode and a platinum anode. The great oxidation ability of this process is due to a large production of hydroxyl radical (OH) by electrochemically induced Fenton’s reagent (H2O2, Fe2+). Hydroxyl radicals are very powerful oxidizing agents which react on organics up to complete mineralization. A factorial experimental design was used for determining the operating parameters on the degradation of 8-HQS in an aqueous medium. The results showed that the …


Synthesizing Bismuth Telluride Nanowires In A Large Scale And Investigating The Energy Filtering Effect By Blending Bismuth Telluride Nanowires And Silver Nanoparticle In Thermoelectrics, Henka Darsono, Haiyu Fang, Yue Wu Oct 2013

Synthesizing Bismuth Telluride Nanowires In A Large Scale And Investigating The Energy Filtering Effect By Blending Bismuth Telluride Nanowires And Silver Nanoparticle In Thermoelectrics, Henka Darsono, Haiyu Fang, Yue Wu

The Summer Undergraduate Research Fellowship (SURF) Symposium

More than 50% of the energy sources becomes “waste” energy generally dissipated to the atmosphere in the form of heat. Thermoelectric effect is a conversion of temperature difference to electric voltage and can be used to convert the wasted heat to useful work. Nanomaterials have great potentials in the field of thermoelectric effect since they have properties that can allow higher efficiency in converting this wasted heat to electricity as compared to bulk materials. The purpose of this project is to develop a method to synthesize bismuth telluride (Bi2Te3) nanowires on a large scale and incorporate …


Stanford Stratified Structure Solver (S4) Simulation Tool, Chang Liu, Xufeng Wang, Peter Bermel Oct 2013

Stanford Stratified Structure Solver (S4) Simulation Tool, Chang Liu, Xufeng Wang, Peter Bermel

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Stanford Stratified Structure Solver (S4) developed in 2012 allows for fast, accurate prediction of optical propagation through complex 3D structures. However, there have been two key challenges preventing wider use to date: the use of a specialized control language, and the difficulty of incorporating realistic materials parameters. In this project, both concerns have been addressed. We have constructed a graphical user interface as an alternative, using the open-source Rappture platform on nanoHUB. This has been combined with a comprehensive materials database known as PhotonicsDB, which incorporates materials optical data drawn from carefully vetted sources. An Octave script file was …


Thread Based Battery For Low Power E-Textile Applications, Pranav Laxmanan, Girish Chitnis, Rahim Rahimi, Babak Ziaie Oct 2013

Thread Based Battery For Low Power E-Textile Applications, Pranav Laxmanan, Girish Chitnis, Rahim Rahimi, Babak Ziaie

The Summer Undergraduate Research Fellowship (SURF) Symposium

Textile electronic systems, or e-textiles, are on the rise but their utility is limited by its power demand. Potential applications include point-of-care diagnostic systems that would enable medical monitoring at the site of care. A small, inexpensive, and easy to use battery would enhance the capabilities of e-textile. Here we propose a thread based battery that attempts to satisfy these requirements. The thread based battery uses chemistry similar to an alkaline battery. The fabrication process involves patterning of current collector (silver epoxy or carbon ink) followed by zinc electroplating and manganese dioxide deposition. Thread present in between these two electrodes …


Small Wind Turbines In Turbulent (Urban) Environments: A Consideration Of Normal And Weibull Distributions For Power Prediction, Keith Sunderland, Thomas Woolmington, Jonathan Blackledge, Michael Conlon Oct 2013

Small Wind Turbines In Turbulent (Urban) Environments: A Consideration Of Normal And Weibull Distributions For Power Prediction, Keith Sunderland, Thomas Woolmington, Jonathan Blackledge, Michael Conlon

Articles

The urban terrain and the associated morphological complexities therein, present significant challenges for the deployment of small wind turbines. In particular, a considerable amount of uncertainty is attributable to the lack of understanding concerning how turbulence within urban environments affects turbine productivity. Current wind turbine power output measurements (particularly for small/micro wind turbines) are based on an average wind speed over an observation period; with limited accountability of the variability of wind speed within the observation time frame. This paper however, presents two models that can instead accurately consider such wind speed variation and how it affects the turbine, based …


Understanding Vehicular Traffic Behavior From Video: A Survey Of Unsupervised Approaches, Brendan Tran Morris, Mohan Manubhai Trivedi Oct 2013

Understanding Vehicular Traffic Behavior From Video: A Survey Of Unsupervised Approaches, Brendan Tran Morris, Mohan Manubhai Trivedi

Electrical & Computer Engineering Faculty Research

Recent emerging trends for automatic behavior analysis and understanding from infrastructure video are reviewed. Research has shifted from high-resolution estimation of vehicle state and instead, pushed machine learning approaches to extract meaningful patterns in aggregates in an unsupervised fashion. These patterns represent priors on observable motion, which can be utilized to describe a scene, answer behavior questions such as where is a vehicle going, how many vehicles are performing the same action, and to detect an abnormal event. The review focuses on two main methods for scene description, trajectory clustering and topic modeling. Example applications that utilize the behavioral modeling …


Photovoltaic Tracker Optimization With Unique Fault Detection And Enhanced Combiner System, Caitlin Nicole Conway Oct 2013

Photovoltaic Tracker Optimization With Unique Fault Detection And Enhanced Combiner System, Caitlin Nicole Conway

Electrical & Computer Engineering Theses & Dissertations

Renewable energy resources are rapidly becoming extremely important as the world's energy consumption continues to rise. The most popular of these resources is solar energy and more specifically photovoltaic energy. Currently, solar modules on the market are still not highly efficient. In order to increase the productivity of solar energy systems, larger fixed-panel photovoltaic systems or tracking photovoltaic systems are utilized. The major disadvantage of larger photovoltaic systems is the increased space requirements. Therefore, tracking photovoltaic systems are the best alternative to achieve higher solar energy yields.

To date, the only method of monitoring tracking photovoltaic systems is with the …


Grid-Tie Arrangements For Micro-Generation Under En50438; An Irish Evaluation, Liam Murphy Sep 2013

Grid-Tie Arrangements For Micro-Generation Under En50438; An Irish Evaluation, Liam Murphy

Conference papers

This paper explores the significance of EN50438 as the standard governing the grid-connection of micro-generation to the distribution network. In the context of micro-generation, EN50438 therefore governs the inverter requirement associated with the majority of micro-generation. Another consideration presented in this research is findings and analysis related to the manufacturers stated efficiency of a grid-tied inverter connected to a Photovoltaic (PV) array in Dublin City Centre, Ireland.


Assessing The Benefits Of Compressed Air Energy Storage On The 2020 Irish Power System, Brendan Cleary, Aidan Duffy, Alan O'Connor, Michael Conlon, Vasilis Fthenakis Sep 2013

Assessing The Benefits Of Compressed Air Energy Storage On The 2020 Irish Power System, Brendan Cleary, Aidan Duffy, Alan O'Connor, Michael Conlon, Vasilis Fthenakis

Conference Papers

Power systems have evolved as countries implement energy policies focusing on energy efficiency and increased share of renewable energy sources (RES). At the forefront is non-dispatchable generation such as wind and solar. Traditionally power systems were designed for fully dispatchable generating plant. However, these powers systems are under additional pressure due to the variable operational characteristics of RES. Consequently, capital investments in grid reinforcement, interconnection, additional gas generators and smart grid initiatives have been proposed and implemented. Moreover, an increased interest in energy storage technologies has evolved due to their various economic and operational benefits to power systems. Current compressed …


Solar Photovoltaic Water Pumping For Multiple Use Systems (Mus) In Nepal, Fintan Mcloughlin, Aidan Duffy, Michael Conlon Sep 2013

Solar Photovoltaic Water Pumping For Multiple Use Systems (Mus) In Nepal, Fintan Mcloughlin, Aidan Duffy, Michael Conlon

Conference Papers

This paper investigates the performance of five solar photovoltaic (PV) Multiple Use Systems (MUS) used for water pumping. The solar MUS’s provide water for drinking, cleaning and micro-irrigation for some of the poorest communities in Nepal. In the absence of data logging, the performance of each system is investigated based on a series of rules of thumb to determine the predicted, expected and estimated demand and supply of water to small rural communities. The systems are compared based on their technical and economic performance and how this relates to local environmental, physical and socioeconomic characteristics at each location.


Maximising Value Of Electrical Networks For Wave Energy Converter Arrays, Fergus Sharkey, Elva Bannon, Michael Conlon, Kevin Gaughan Sep 2013

Maximising Value Of Electrical Networks For Wave Energy Converter Arrays, Fergus Sharkey, Elva Bannon, Michael Conlon, Kevin Gaughan

Articles

Currently there are the beginnings of a commercial wave energy industry and the ultimate ambition will be to deploy Wave Energy Converters (WECs) in arrays, or wave farms, in a similar fashion to offshore wind. These arrays will require electrical networks to collect and export the generated electrical power to shore and onto the electrical grid. For large scale wind farms the inter-array and export electrical networks can represent more than 20% of the project’s capital expenditure. Submarine power cables account for a large proportion of this cost. The same is expected to be the same for WEC arrays.

This …


Urban Deployment Of Small Wind Turbines: Power, Performance And Turbulence, Keith Sunderland, Thomas Woolmington, Michael Conlon, Jonathan Blackledge Sep 2013

Urban Deployment Of Small Wind Turbines: Power, Performance And Turbulence, Keith Sunderland, Thomas Woolmington, Michael Conlon, Jonathan Blackledge

Conference papers

The urban terrain and the associated topographical complexities therein, present significant challenges to the deployment of small wind turbines. In particular, a considerable amount of uncertainty is attributable to the lack of understanding concerning how turbulence within urban environments affects turbine productivity. This paper considers how the industry standard metric, turbulence intensity (TI), in conjunction with the power characteristic of a 2.5kW wind turbine, can be employed to estimate turbine power performance. The research presented here considers the potential productivity of a wind turbine installation at two sites in (urban and suburban) Dublin, Ireland where the prevalent turbulence at both …


Impacts On The Electrical System Economics From Critical Design Factors Of Wave Energy Converters And Arrays, Fergus Sharkey, Michael Conlon, Kevin Gaughan Sep 2013

Impacts On The Electrical System Economics From Critical Design Factors Of Wave Energy Converters And Arrays, Fergus Sharkey, Michael Conlon, Kevin Gaughan

Conference papers

It is expected that ultimately, like offshore wind farms, electrical systems will make up to a quarter of the overall Capex of wave farms. This is a significant element of cost and consideration must be taken in the design of both individual wave energy converters (WECs) and arrays of WECs to ensure that these costs can be minimised. In a worst case scenario design decisions could increase the cost of the electrical system by several orders and ultimately make the technology uncompetitive.

This paper outlines the impacts on the cost of the electrical system arising from design factors of WECs …


The Domestic And Export Market For Large Scale Wave Energy In Ireland And The Economics Of Export Transmission, Fergus Sharkey, Kevin Honer, Michael Conlon, Kevin Gaughan, Emma Robinson Sep 2013

The Domestic And Export Market For Large Scale Wave Energy In Ireland And The Economics Of Export Transmission, Fergus Sharkey, Kevin Honer, Michael Conlon, Kevin Gaughan, Emma Robinson

Conference papers

Ireland is on track to meet its 2020 renewable energy targets with over 2 GW of onshore wind installed in the all island market as of 2013, and a multiple of this capacity in various stages of planning and development. It is currently unclear how much of this potential capacity will ultimately be installed but it has become clear that the wind industry in Ireland will change focus to export opportunities post 2020. This presents some interesting challenges for wave energy in Ireland.

There is some early activity in the installation of wave farms off the west coast of Ireland …


Electrosynthesis Of Glycerol Carbonate From Co2 And Glycerol, Huan Wang, Mei-Xia Zhu, La-Xia Wu, Xiao-Ming Xu, Xue-Ru Zhao, Jia-Xing Lu Aug 2013

Electrosynthesis Of Glycerol Carbonate From Co2 And Glycerol, Huan Wang, Mei-Xia Zhu, La-Xia Wu, Xiao-Ming Xu, Xue-Ru Zhao, Jia-Xing Lu

Journal of Electrochemistry

Glycerol carbonate was obtained from glycerol and carbon dioxide under room temperature and normal pressure by electrochemical method. The effects of synthesis conditions, such as cathode, charge, current density and temperature, on the reaction of glycerol and carbon dioxide have been investigated. The yields of 73% were produced by electrosynthesis of carbonate under the optimized condition, which is much higher than that by common catalysis method. The electrochemical behavior of the reaction system has been studied by cyclic voltammetry, through which the reaction process has been proposed.


Influence Of Pretreatment On Electrocatalytic Property For Methanol Oxidation Of Ptru/Wc, Xiao-Ling Lang, Mei-Qin Shi, Ye-Kun Jiang, Chun-An Ma Aug 2013

Influence Of Pretreatment On Electrocatalytic Property For Methanol Oxidation Of Ptru/Wc, Xiao-Ling Lang, Mei-Qin Shi, Ye-Kun Jiang, Chun-An Ma

Journal of Electrochemistry

The surface of tungsten carbide (WC) was treated by potassium hydroxide (KOH) at different pH values for different time. The PtRu/WC composite was prepared by microwave-assisted polyol method. The phase structure of PtRu/WC composites were characterized by XRD. The electrocatalytic activity was tested by cyclic voltammetry and chronoamperometry. The results indicated that with different pH treatments WC became more readily supported on PtRu. When treating WC in KOH at pH = 14, PtRu exhibited the best degree of crystallinity on WC surface, leading to the highest electrocatalytic activity of PtRu/WC. Moreover, the optimized activity of PtRu/WC towards methanol oxidation was …


Synthesis And Electrochemical Properties Of Li(Ni0.5Co0.2Mn0.3)1-2xTiXNbXO2, Yong Tang, Qin-Lin Liao, Xiang-An Guo Aug 2013

Synthesis And Electrochemical Properties Of Li(Ni0.5Co0.2Mn0.3)1-2xTiXNbXO2, Yong Tang, Qin-Lin Liao, Xiang-An Guo

Journal of Electrochemistry

The cathode-active materials of layered Li(Ni0.5Co0.2Mn0.3)1-2xTixNbxO2(x=0, 0.002, 0.005, 0.01, 0.02)composites were synthesized by the thermal treatment of the coprecipitated precursor at 900 oC in air. The effects of Ti-Nb co-dopants on the structural and electrochemical properties of Li(Ni0.5Co0.2Mn0.3)O2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical experiments. The results show that the small amounts of Ti-Nb co-dopants in Li(Ni0.5Co0.2Mn0.3)O2significantly decreased the degree of cation mixing in …


Effects Of Fluoroethylene Carbonate Additive On Low Temperature Performance Of Li-Ion Batteries, Feng-Ju Bian, Zhong-Ru Zhang, Yong Yang Aug 2013

Effects Of Fluoroethylene Carbonate Additive On Low Temperature Performance Of Li-Ion Batteries, Feng-Ju Bian, Zhong-Ru Zhang, Yong Yang

Journal of Electrochemistry

The effects of fluoroethylene carbonate (FEC) on the low temperature performance of lithium ion phosphate full battery are evaluated by different techniques. By addition of 5 wt% FEC into a commercial electrolyte, effective solid electrolyte interface (SEI) film can be formed on the graphite electrodes, the discharge capacity retention at -40 oC was increased from 31.7% to 43.7%, and the discharge voltage plateau of the cell is raised. This is attributed to a reduced charge transfer resistance and a lowered polarization on the graphite electrode by electrochemical impedance spectroscopy (EIS) and reference electrode test.