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Full-Text Articles in Power and Energy

Mini High Temperature Test Unit Final Design Report, Kevin Liu, Juan P. Castillo Jun 2017

Mini High Temperature Test Unit Final Design Report, Kevin Liu, Juan P. Castillo

Mechanical Engineering

Lawrence Livermore National Laboratory has invested considerable effort to develop new standard for nuclear grade HEPA filters that can withstand high temperatures along with methods to optimally test not only the experimental filter media, but also new frame seals and media binders. Therefore, LLNL in collaboration with Cal Poly has designed and built a Mini High Temperature Testing Unit (MHTTU) to recreate conditions observed during a fire and to test different materials in an effective, inexpensive, regulated and reliable method. The existing prototype was unable to achieve the ideal testing conditions of 1000°F air at the low flow rates of …


Marine Gastrobot Final Design Report, Wesley B. Williams, Eric Kane Dreischerf, Tommy Nicholas Yath Jun 2017

Marine Gastrobot Final Design Report, Wesley B. Williams, Eric Kane Dreischerf, Tommy Nicholas Yath

Mechanical Engineering

The Marine Gastrobot sponsored by Dr. Christopher Kitts of the Cal Poly Center for Applications in Biotechnology was a research and development effort intended to explore the use of microbial fuel cell technology as a power source for underwater robots. Our team Ocean Locomotion succeeded in developing a first iteration of an underwater robotic platform suitable for microbial fuel cell integration. The primary feature of the design is its sinusoidal fin propulsion intended for benthic exploration with limited risk of entanglement. During the course of development, Ocean Locomotion explored the use of low power actuation methods and determined their limited …


Design And Construction Of 1800w Modular Multiple Input Single Output Non-Isolated Dc-Dc Converters, Angelo Miguel Asuncion Gallardo Jun 2017

Design And Construction Of 1800w Modular Multiple Input Single Output Non-Isolated Dc-Dc Converters, Angelo Miguel Asuncion Gallardo

Master's Theses

This thesis report details the design and construction of non-isolated DC-DC converters to create a Multiple Input Single Output (MISO) converter for combining multiple renewable energy sources into one single output. This MISO uses the four-switch buck-boost topology to output a single 48V from multiple nominal 24V inputs. The MISO converter implements a modular approach to deliver 1800W output power. Each module in the MISO is rated at 600W and they share the output power equally. Hardware results show that the converter produces 1800W of output power from three sources with 96.4% efficiency. Each module also demonstrates equal sharing feature …


A Modified Boost Converter With Reduced Input Current Ripple, Nathan H. Lentz Jun 2017

A Modified Boost Converter With Reduced Input Current Ripple, Nathan H. Lentz

Master's Theses

Battery-powered trends in consumer electronics, transportation, and renewable energy sectors increase demands on DC/DC converter technology. Higher switching frequency and efficiency reduces solution size and cost, while increasing power capabilities. Still, switching noise remains the primary drawback associated with any DC/DC converter. Reducing a converter’s input ripple helps prevent switching noise from spreading to other systems on a shared DC power bus. This thesis covers the analysis, simulation, and implementation of a recently-proposed boost converter topology, alongside an equivalent standard boost converter, operating in steady-state, continuous conduction mode. A Matlab-based simulation predicts each converter’s input ripple performance using a state-space …


Dc-Dc Converter Control System For The Energy Harvesting From Exercise Machines System, Alexander Sireci Jun 2017

Dc-Dc Converter Control System For The Energy Harvesting From Exercise Machines System, Alexander Sireci

Master's Theses

Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states.

An artificial neural …


Generalized Differential Calculus And Applications To Optimization, R. Blake Rector Jun 2017

Generalized Differential Calculus And Applications To Optimization, R. Blake Rector

Dissertations and Theses

This thesis contains contributions in three areas: the theory of generalized calculus, numerical algorithms for operations research, and applications of optimization to problems in modern electric power systems. A geometric approach is used to advance the theory and tools used for studying generalized notions of derivatives for nonsmooth functions. These advances specifically pertain to methods for calculating subdifferentials and to expanding our understanding of a certain notion of derivative of set-valued maps, called the coderivative, in infinite dimensions. A strong understanding of the subdifferential is essential for numerical optimization algorithms, which are developed and applied to nonsmooth problems in operations …


Iii-Nitride Nanowire Light-Emitting Diodes: Design And Characterization, Dipayan Datta Choudhary May 2017

Iii-Nitride Nanowire Light-Emitting Diodes: Design And Characterization, Dipayan Datta Choudhary

Theses

III-nitride semiconductors have been intensively studied for optoelectronic devices, due to the superb advantages offered by this materials system. The direct energy bandgap III-nitride semiconductors can absorb or emit light efficiently over a broad spectrum, ranging from 0.65 eV (InN) to 6.4 eV (AlN), which encompasses from deep ultraviolet to near infrared spectrum. However, due to the lack of native substrates, conventional III-nitride planar heterostructures generally exhibit very high dislocation densities that severely limit the device performance and reliability. On the other hand, nanowire heterostructures can be grown on lattice mismatched substrates with drastically reduced dislocation densities, due to highly …


Operating Temperature Of A Solar Thermal Stirling Engine, Spencer Beck May 2017

Operating Temperature Of A Solar Thermal Stirling Engine, Spencer Beck

Senior Theses

This paper explores the relationship between the operating temperature and electricity production of a simple heat engine. A Stirling engine was designed and constructed which runs on solar thermal energy collected by a Fresnel lens. The surface area of the solar collector was varied. This manipulated the operating temperature of the Stirling engine in order to measure power output. The mechanical energy from the engine was converted to electricity using a DC motor running in reverse, acting like a generator, in conjunction with an Arduino for data collection. Although adjustments must be made in order to improve the efficiency of …


Are Solar Panels A Viable Power Source For A Green Energy Vehicle?, Mason C. Adams May 2017

Are Solar Panels A Viable Power Source For A Green Energy Vehicle?, Mason C. Adams

Senior Theses

A solar cell powered go-kart has been built and tested. The result shows using solar energy alone cannot meet the requirement of running a regular passenger car. This is due to the limited surface area of the passenger car. This thesis also discusses the operating principles of solar panels, the physics of P type and N type semiconductors, and the formation of the PN junction, as well as the solar current. Modifications of an existing go-kart are described in detail in this thesis. Suggestions for making green vehicles are discussed as well.


Determination Of Single Pole Breaker Reclose Time And System Performance Using Real Time Simulation, Venkata Sridivya Godavarthi May 2017

Determination Of Single Pole Breaker Reclose Time And System Performance Using Real Time Simulation, Venkata Sridivya Godavarthi

LSU New Orleans Theses and Dissertations

This thesis investigates single pole reclosing in series capacitor compensated line. An algorithm is developed to determine the optimal dead time required for single pole reclose of circuit breakers and to reduce the randomness of reclosing time. The algorithm considers conditions of system, fault, voltage zero crossing, arc, and IEEE C37.104-2012 standard de-ionization time. This study also addresses difficulties of single pole reclose operation such as over-voltages at the line, secondary arc extinguishing time, dead time, over-voltages across the series capacitor, and negative sequence current. The system performance is evaluated using a set of metrics based on those operation difficulties. …


2017 Spring Engr333 Project Final Report (Section A), Devin Auld, Scott Bokach, Joshua Bronner, Alex Meador, Ryan Hoek, Robert Lanser, Matthew Lenko, Elliot Slenk, Brendan Biesboer, Kyle Mailhot, Nate Zylstra, Jonah Engel, Rich Floro, Björn Krebs, Ethan Postmus, Cameron Bell, Caleb Bieske, Chris Griffin, Bernice Portugal, Ryan Beezhold, Dillon Carhuff, Ian Mcclaskie, Jared Vanderklay, Rounak Chatterjee, Toby Dalla Santa, Jenny Haney, Joel Hoskins, Caleb Senyshyn May 2017

2017 Spring Engr333 Project Final Report (Section A), Devin Auld, Scott Bokach, Joshua Bronner, Alex Meador, Ryan Hoek, Robert Lanser, Matthew Lenko, Elliot Slenk, Brendan Biesboer, Kyle Mailhot, Nate Zylstra, Jonah Engel, Rich Floro, Björn Krebs, Ethan Postmus, Cameron Bell, Caleb Bieske, Chris Griffin, Bernice Portugal, Ryan Beezhold, Dillon Carhuff, Ian Mcclaskie, Jared Vanderklay, Rounak Chatterjee, Toby Dalla Santa, Jenny Haney, Joel Hoskins, Caleb Senyshyn

ENGR 333

The objective of ENGR-333-A was to develop a well-defined, bottom-up energy demand model for the energy consumption of the dormitories on Calvin College’s campus for each year of the past decade within an accuracy of ± 2%.


2017 Spring Engr333 Project Final Report (Section B), Daniel Dick, Nathan Swaim, Jonathan Sager, Ellen Reidy, Jordan Swets, Joel Van Dyke, Connor Macdonald, Josiah Markvluwer, Justin Rohlicek, John Lee, Zach Mouw, Daniel Wharton, Sam Hanover, Jay Noyola, Adam Christenson, Scott Stamper, Aaron Tucker, Bethany Waanders, Joel Schaefer, Maddie Collins, Matthew Cok, Philip Kim, Steve Vanden Berg May 2017

2017 Spring Engr333 Project Final Report (Section B), Daniel Dick, Nathan Swaim, Jonathan Sager, Ellen Reidy, Jordan Swets, Joel Van Dyke, Connor Macdonald, Josiah Markvluwer, Justin Rohlicek, John Lee, Zach Mouw, Daniel Wharton, Sam Hanover, Jay Noyola, Adam Christenson, Scott Stamper, Aaron Tucker, Bethany Waanders, Joel Schaefer, Maddie Collins, Matthew Cok, Philip Kim, Steve Vanden Berg

ENGR 333

The Physical Education Complex is located in the North-end of Calvin College’s campus, and supports many athletic, academic, event and recreational functions. Due to its heavy use, the complex contributes 20% of the College’s electricity consumption. Monetarily, this equated to electricity costs of about $385,000 last year. With these financial implications, the College is searching for ways to reduce the cost. While there is little to no room for electricity cost rate reductions, there is opportunity for improvement through the implementation of more efficient components. However, the sources of electricity demand are largely unknown. Our objective is to develop a …


2017 Spring Engr333 Seminar Presentation, Jonah Engel, Rich Floro, Björn Krebs, Ethan Postmus, Brendan Biesboer, Kyle Mailhot, Nate Zylstra, Ryan Beezhold, Dillon Carhuff, Ian Mcclaskie, Jared Vanderklay, Rounak Chatterjee, Toby Dalla Santa, Jennifer Haney, Joel Hoskins, Caleb Senyshyn, Alex Meador, Scott Bokach, Devin Auld, Joshua Bronner, Elliot Slenk, Matthew Lenko, Robert Lanser, Ryan Hoek, Cameron Bell, Caleb Bieske, Chris Griffin, Bernice Portugal, Sam Hanover, Dan Wharton, Jay Noyola, Zachary Mouw, John Lee, Daniel Dick, Jonathan Sager, Nathan Swaim, Ellen Reidy, Jordan Swets, Joel Van Dyke, Connor Macdonald, Josiah Markvluwer, Justin Rohlicek, Adam Christensen, Scott Stamper, Aaron Tucker, Bethany Waanders, Joel Schaefer, Maddie Collins, Matthew Cok, Philip Kim, Steve Vanden Berg May 2017

2017 Spring Engr333 Seminar Presentation, Jonah Engel, Rich Floro, Björn Krebs, Ethan Postmus, Brendan Biesboer, Kyle Mailhot, Nate Zylstra, Ryan Beezhold, Dillon Carhuff, Ian Mcclaskie, Jared Vanderklay, Rounak Chatterjee, Toby Dalla Santa, Jennifer Haney, Joel Hoskins, Caleb Senyshyn, Alex Meador, Scott Bokach, Devin Auld, Joshua Bronner, Elliot Slenk, Matthew Lenko, Robert Lanser, Ryan Hoek, Cameron Bell, Caleb Bieske, Chris Griffin, Bernice Portugal, Sam Hanover, Dan Wharton, Jay Noyola, Zachary Mouw, John Lee, Daniel Dick, Jonathan Sager, Nathan Swaim, Ellen Reidy, Jordan Swets, Joel Van Dyke, Connor Macdonald, Josiah Markvluwer, Justin Rohlicek, Adam Christensen, Scott Stamper, Aaron Tucker, Bethany Waanders, Joel Schaefer, Maddie Collins, Matthew Cok, Philip Kim, Steve Vanden Berg

ENGR 333

File for student presentation, given by students in the Spring 2017 class of ENGR333.


Methanol Steam Reforming: Na Doping Of Pt/Ysz Provides Fine Tuning Of Selectivity, Michela Martinelli, Gary Jacobs, Uschi M. Graham, Burtron H. Davis May 2017

Methanol Steam Reforming: Na Doping Of Pt/Ysz Provides Fine Tuning Of Selectivity, Michela Martinelli, Gary Jacobs, Uschi M. Graham, Burtron H. Davis

Center for Applied Energy Research Faculty and Staff Publications

In this work, we found that sodium doping can be used to improve CO2 selectivity for supported Pt catalyst during methanol steam reforming. These materials are usually very active in the low temperature range; however, they are characterized by high selectivity of CO, which is a poison in downstream polymer electrolyte membrane fuel cells (PEM-FC) application. With Na doping, we found that CO2 selectivity was higher than 90% when 2.5 wt.% of sodium was added to Pt/YSZ. We have speculated that the different product distribution is due to a different reaction pathway being opened for CH3OH …


Development Of Intermediate Band Solar Cell Through Ingan Quantum Well Structures, Kelly Mckenzie May 2017

Development Of Intermediate Band Solar Cell Through Ingan Quantum Well Structures, Kelly Mckenzie

Electrical Engineering Undergraduate Honors Theses

In the search for high-efficiency solar cells, InxGa1-xN has come under scrutiny as a unique material with high potential. This is due to characteristics including an easily tunable bandgap, large range of potential bandgap values, and high heat resistance. However, one factor limiting its adaptation is the high density of crystal defects. In this thesis, the qualities of InGaN are discussed and the intermediate band solar cell structure is introduced. Additionally, the growth and characterization of two sets of InGaN-based solar cell devices are reported and evaluated.


Protective Relaying Student Laboratory, Kenan W. Pretzer May 2017

Protective Relaying Student Laboratory, Kenan W. Pretzer

Master's Theses

Facing a rapidly-changing power industry, the electrical engineering department at Cal Poly San Luis Obispo proposed Advanced Power Systems Initiatives to better prepare its students for entering the power industry. These initiatives call for the creation of a new laboratory curriculum that uses microprocessor-based relays to reinforce the fundamental concepts of power system protection. This paper summarizes a laboratory system fit for this task and presents a set of proposed laboratory experiments to establish a new laboratory course at Cal Poly. The experiments expose students to the capabilities of industry-standard microprocessor-based relays through hands-on procedures that demonstrate common power system …


On The Effect Of Design Tolerances On The Performance Of Synchronous Pm Machines Evaluated According To The Ieee Std 1812, Narges Taran, Vandana Rallabandi, Dan M. Ionel, Ping Zhou May 2017

On The Effect Of Design Tolerances On The Performance Of Synchronous Pm Machines Evaluated According To The Ieee Std 1812, Narges Taran, Vandana Rallabandi, Dan M. Ionel, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

In the process of designing an electric machine, the systematic study of tolerances for the design variables and material properties is of the utmost importance. This paper proposes a method by which possible variations of the design variables and material properties can be distinguished. The design of experiments (DOE) technique, open-circuit and short-circuit tests, with minimum instrumentation requirements, have been employed. Virtual tests are conducted based on the recently approved IEEE 1812 testing guide for PM synchronous machines. As a case study, a 100 hp 16-pole 18-slot spoke-type PM machine is discussed. It is shown that variation in magnet remanence, …


Axial-Flux Pm Synchronous Machines With Air-Gap Profiling And Very High Ratio Of Spoke Rotor Poles To Stator Concentrated Coils, Vandana Rallabandi, Narges Taran, Dan M. Ionel, Ion G. Boldea May 2017

Axial-Flux Pm Synchronous Machines With Air-Gap Profiling And Very High Ratio Of Spoke Rotor Poles To Stator Concentrated Coils, Vandana Rallabandi, Narges Taran, Dan M. Ionel, Ion G. Boldea

Power and Energy Institute of Kentucky Faculty Publications

Permanent magnet machines including a magnetic gearing effect are attractive for low-speed high-torque applications. This paper proposes a dual-stator axial-flux machine topology with a high ratio for the number of rotor poles to concentrated stator coils. The stator consists of a relatively small number of teeth, with each tooth including multiple smaller/auxiliary teeth. The rotor employs spoke-type permanent magnets, which result in high flux concentration, thereby further improving the torque density. The paper discusses the principle of operation of the proposed machine topology. Finite element results on example designs with 6 stator teeth, each having 2 and 3 auxiliary teeth, …


Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young May 2017

Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young

Graduate Theses and Dissertations

The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type …


Wireless Charging For Bluetooth Earphones, Daniel Carlson May 2017

Wireless Charging For Bluetooth Earphones, Daniel Carlson

Electrical Engineering

This project involves designing and building an inductive charging system for Bluetooth earphones. This system provides a charging dock for a pair of retrofitted Bluetooth earphones and focuses on ease-of-use and convenience for the user. The motivations for this project include providing charging compatibility to changing audio technology and trends. Smart phones and other audio products are increasingly leaning towards wireless (Bluetooth) audio, and wireless headphones/headsets are naturally becoming more prevalent to match this trend. A small, easy to use, and efficient charging dock for these earphones seems like a necessary accessory for this technology to seem attractive to consumers. …


A Novel Time-Domain Method Of Fault Diagnosis In Induction Motors, Bryan J. Davis May 2017

A Novel Time-Domain Method Of Fault Diagnosis In Induction Motors, Bryan J. Davis

Honors Scholar Theses

This paper introduces a novel time-domain method for detecting the four major types of induction motor faults without requiring complex signal processing or additional sensors other than those already in place for closed-loop motor control. This method artificially modulates the motor current feedback signal with a perturbed frequency that oscillates about the characteristic frequency of the fault in question. After filtering out the unwanted frequency components that result from the modulation, the selected fault-indicative component is a very slow sinusoid that is only present when the fault is present. The method looks for this fault-indicative component by monitoring the time …


Optimization Of Graphene Parameters For The Development Of Supercapacitors, Jessica L. Montgomery May 2017

Optimization Of Graphene Parameters For The Development Of Supercapacitors, Jessica L. Montgomery

Mechanical Engineering Undergraduate Honors Theses

In the growing market of evolving electronic devices and the sustainable goals of the energy industry, better sources of energy dense storage devices are needed. Carbon based supercapacitors have attracted the attention of research due to the natural properties of high electrical conductivity, chemical and electrochemical stability, and high surface area. The object of this thesis is to expand upon current knowledge of reduced graphene oxide to better understand the effectiveness of the material as electrode in supercapacitors. This thesis will focus on the physical orientation of supercapacitors to further develop a device that will allow a set of supercapacitors …


System-Layout-Dependent Thermally Induced Solder Stress & Reliability Implications, Ange C. Iradukunda May 2017

System-Layout-Dependent Thermally Induced Solder Stress & Reliability Implications, Ange C. Iradukunda

Mechanical Engineering Undergraduate Honors Theses

Electronic flip chip assemblies consist of dissimilar component materials, which exhibit different CTE. Under thermal cyclic operating conditions, this CTE mismatch produces interfacial and interconnect stresses, which are highly dependent on system layout. In this paper, sensitivity analyses are performed using ANSYS FEA to establish how the proximity and arrangement of neighboring devices affect interconnect stress. Flip chip alignment modes ranging from edge-to-edge to corner-to-corner are studied. Results of these FEA studies, demonstrated that closely packing devices together has the effect of making them act as one. This results in a significant increase in the thermomechanical stresses induced on peripheral …


Linear Quadratic Optimal Control For A Cascaded Converters-Based Microgrid, Amlam Niragire May 2017

Linear Quadratic Optimal Control For A Cascaded Converters-Based Microgrid, Amlam Niragire

Graduate Theses and Dissertations

There is a constant transformation of the electric grid due to an ongoing interest in the deployment of renewable energy resources and electric microgrid formation. This transformation, though advantageous in many ways, poses great challenges for the energy industry and there must be a constant improvement in modeling, simulation, analysis and control techniques in order to characterize and optimize the system design and operation. In this light, the scope of this thesis is focused on developing a linear model, analyzing the stability and designing an optimal linear quadratic regulator (LQR) for a microgrid system. The microgrid system used is inspired …


Applications Of Krylov Subspace And Balanced Truncation Model Order Reduction In Power Systems, Sebastian Emanuel Garrido May 2017

Applications Of Krylov Subspace And Balanced Truncation Model Order Reduction In Power Systems, Sebastian Emanuel Garrido

Graduate Theses and Dissertations

Dynamic representations of power systems usually result in the order of hundreds or even thousands of buses. Therefore, reduction of these dynamic representations is convenient. Two applications of model order reduction in power systems are discussed in this thesis. First, Krylov subspace-based method is applied to the IEEE-123 Node Test Feeder in the context of distribution-level power systems simulation. Second, a Balanced Truncation-based model reduction is implemented in the 3-Machine 9-Bus system for designing a power system controller in the context of generation- and transmission-level power systems.

First, for the IEEE-123 Node Test Feeder, a two-sided Arnoldi algorithm is proposed …


Energy Harvesting From Exercise Machines: Comparative Study Of Ehfem Performance With Dc-Dc Converters And Dissipative Overvoltage Protection Circuit, Cameron Kiddoo May 2017

Energy Harvesting From Exercise Machines: Comparative Study Of Ehfem Performance With Dc-Dc Converters And Dissipative Overvoltage Protection Circuit, Cameron Kiddoo

Master's Theses

Energy Harvesting from Exercise Machines (EHFEM) is an ongoing project pursuing alternate forms of sustainable energy for Cal Poly State University. The EHFEM project seeks to acquire user-generated DC power from exercise machines and sell that energy back to the local grid as AC power. The end goal of the EHFEM project aims to integrate a final design with existing elliptical fitness trainers for student and faculty use in Cal Poly’s Recreational Center. This report examines whether including the DC-DC converter in the EHFEM setup produces AC power to the electric grid more efficiently and consistently than an EHFEM system …


Hardware Realization Of A Residential Static Var Compensator, Muhammad Kamran Latif May 2017

Hardware Realization Of A Residential Static Var Compensator, Muhammad Kamran Latif

Boise State University Theses and Dissertations

Conservation by Voltage Reduction (CVR) is the implementation of a distribution voltage strategy whereby all distribution voltages are lowered to the minimum allowed by the equipment manufacturer. This strategy is rooted in the fact that many loads consume less power when they are fed with a voltage lower than nominal. Electric utility companies consider CVR as a potential solution for managing power in distribution networks. However, a difficult challenge is to keep end-of-line (EOL) voltages within an acceptable range of the ANSI Standard C84.1. Therefore, to achieve maximum benefit from CVR, electric utilities should be able to regulate residential voltages …


Novel Composites Between Nano-Structured Nickel Sulfides And Three-Dimensional Graphene For High Performance Supercapacitors, Xiaomin Wang, Huanglin Dou, Zhen Tian, Jiujun Zhang Apr 2017

Novel Composites Between Nano-Structured Nickel Sulfides And Three-Dimensional Graphene For High Performance Supercapacitors, Xiaomin Wang, Huanglin Dou, Zhen Tian, Jiujun Zhang

Journal of Electrochemistry

In this paper, a three-dimensional graphene (3DG) network grown on nickel foam was employed as a template for synthesizing graphene-based composite materials of supercapacitor electrode. The composites (crystal Ni3S2 nanorods on the surface of 3DG (abbreviated as Ni3S2/3DG)) were obtained through a one-step hydrothermal reaction. The morphological and structural evolution of the Ni3S2/3DG composites were investigated by SEM, TEM, XRD and Raman spectroscopy. Detailed electrochemical characterization showed that the Ni3S2/3DG-coated electrodes exhibited both a specific capacitance as high as 1825 F·g-1 at 5 mV·s …


Designing Pt-Skin Of Pt-Based Bimetallic Electrocatalysts For Oxygen Reduction Reaction, Binwei Zhang, Yunxiao Wang, Yanfei Xu, Huakun Liu, Shixue Dou Apr 2017

Designing Pt-Skin Of Pt-Based Bimetallic Electrocatalysts For Oxygen Reduction Reaction, Binwei Zhang, Yunxiao Wang, Yanfei Xu, Huakun Liu, Shixue Dou

Journal of Electrochemistry

In the past decade, great advancement has been made in the development of nanocatalysts for energy conversion and storage. Pt-skin of Pt-based bimetallic has shown a great potential in the tuning the electronic structures of electrocatalytically active materials toward oxygen reduction reaction. Here, we offer a brief overview of the recent research on the design and preparation of catalysts. Our focus is paid on the systematic studies of preparation and performance of Pt-skin catalysts towards oxygen reduction reaction.


Recent Progress In Template-Assisted Synthesis Of Nitrogen-Doped Porous Carbons For Oxygen Electroreduction, Wenhan Niu, Ligui Li, Shaowei Chen Apr 2017

Recent Progress In Template-Assisted Synthesis Of Nitrogen-Doped Porous Carbons For Oxygen Electroreduction, Wenhan Niu, Ligui Li, Shaowei Chen

Journal of Electrochemistry

Nitrogen (N)-doped porous carbons are potential alternatives to precious metal catalysts for oxygen reduction reaction (ORR) at the cathodes of proton exchange membrane fuel cells and metal-air batteries. Template-assisted synthesis has been used extensively as a robust and versatile method in the preparation of such carbon catalysts, where the ORR activity has been found to be dependent on various structural parameters, such as the concentrations and molecular configurations of the dopants, and the porosity, surface accessibility and electrical conductivity of the carbon materials. In this review, we summarize recent progress in this area of research focusing on the design, preparation …