Power and Energy Commons^™

Research Status And Application Prospects Of Limnpo4 As A New Generation Cathode Material For Lithium-Ion Batteries, Lai-Fen Qin, Yong-Gao Xia, Li-Peng Chen, Hua-Sheng Hu, Feng Xiao, Zhao-Ping Liu

Journal of Electrochemistry

Olivine-structured lithium manganese phosphate (LiMnPO₄) has the following advantages: excellent thermal stability, low cost, high safety and environmental benignity. Importantly, the theoretical energy density of LiMnPO₄ is about 20% higher than that of commercialized LiFePO₄ due to its higher Li⁺ intercalation potential of 4.1 V (vs. Li⁺/Li). Moreover, the high operating voltage of LiMnPO₄ is compatible with present non-aqueous organic electrolytes of lithium-ion batteries. Therefore, LiMnPO₄ is considered as a next generation cathode material for lithium-ion batteries. However, LiMnPO₄ suffers from poor electronic conductivity and low lithium diffusivity, resulting in …

Preparations And Applications Of Layered Carbon And Layered Carbon-Pbso4 Composite, Shu-Kai Zhang, Hao Zhang, Wei-Hua Xue, Jie Cheng, Wen-Feng Zhang, Gao-Ping Cao, Hai-Lei Zhao, Yu-Sheng Yang

Journal of Electrochemistry

The layered carbon materials (similar to graphene) have been synthesized by chemical vapor deposition (CVD) on the cheap catalyst (potassium or sodium carbonate substrate). The layered-carbon- lead sulfate (PbSO₄) composite could be prepared by in situ chemical deposition based on the layered carbon. The XRD, SEM and TEM results showed that the layered carbon materials was amorphous carbon layer, and the composite was a compound made of fine lead sulfate grains and layered carbon. Thermogravimetric analysis determined the carbon content in the composite. Adding a certain amount of layered carbon or layered-carbon-PbSO₄ composite into negative active materials …

Electrochemical Mass Spectrometric Study Of Lithium-Oxygen Batteries, Xin-Xiu Yan, Li-Po Ma, Zhang-Quan Peng

Journal of Electrochemistry

Mass Spectrometry, coupled with electrochemistry, is a powerful research tool to study mechanisms for a broad range of electrode reactions by identifying and quantifying reaction products and intermediates. In this review, we summarize the recent advances in the Li-O₂ battery researches offered by electrochemical mass spectrometry based on our group investigations. These include the research progresses in electrolytes, cathode materials (electrocatalysts), and parasitic reactions, i.e., the key issues associated with Li-O₂ research. In addition, we also discuss the effects of irreversible side reactions involved in battery systems on charge and discharge processes.

Synthesis Of Graphene Wrapped Li-Rich Layered Metal Oxide And Its Electrochemical Performance, Meng-Yan Hou, Ke Wang, Xiao-Li Dong, Yong-Yao Xia

Journal of Electrochemistry

In present work, lithium-rich layered transition metal oxide (LLO) was synthesized by a co-precipitation method in combination with a solid-state reaction. The graphene wrapped Li-rich layered oxide composite (LLO/Gra) was obtained by sintering the LLO/GO composite at 300 ^oC for 30 min in an air. The morphologies and the electrochemical performances were characterized by means of SEM, TEM, XRD, XPS, EIS and charge/discharge tests. The results indicated that the LLOe particles were uniformly wrapped with graphene. The resulting material exhibited better rate capability than that of pristine LLO since the wrapped graphene demonstrated the enhanced electronic conductivity. Accordingly, the …

Research Progress In Carbon Coating On Lifepo4 Cathode Materials For Lithium Ion Batteries, Ning Zhang, Yong-Chang Liu, Cheng-Cheng Chen, Zhi-Qiang Zhu, Zhan-Liang Tao, Jun Chen

Journal of Electrochemistry

Olivine-structured LiFePO₄ has been received much attention because of its flat voltage profile, low cost, abundant material supply and better environmental compatibility. However, the poor electronic and ionic conductivities have limited its application in industry. One of the best methods to improve the electrochemical performance is carbon coating. In this review, we summarize the recent developments of LiFePO₄/C cathode. Moreover, the different effects caused by coating methods and carbon sources, as well as the mechanism of carbon coating on the properties of LiFePO₄/C are reviewed.

Enhancing Stability Of Pem Fuel Cell Catalysts Via Support Changing, Xiao-Hong Xie, Zi-Dong Wei

Journal of Electrochemistry

The Pt/C catalyst with highly dispersed Pt nanoparticles supported on carbon has been widely used as the state-of the-art catalyst in proton exchange membrane fuel cells (PEMFCs), while the durability of Pt/C is one of the major barriers for large-scale applications of PEMFCs. Thus, enhancing the stability of Pt/C has been a hot issue in this field. In this review, we summarize the recent progress in enhancing the catalyst stability in the view of support material. The future prospects of the PEMFCs catalyst should focus on adopting more stable supports or strengthening the interactions between Pt and supports.

Pt/C Modified Proton Exchange Membrane For Improved Fuel Cell Performance, Zhi Cui, Chao Wang, Shui-Yun Shen, Feng-Jing Jiang, Jun-Liang Zhang

Journal of Electrochemistry

The property of proton exchange membrane greatly affects the performance of proton exchange membrane fuel cells (PEMFC). During the operation of a PEMFC, the water produced at the cathode, the water vapor from the humidified feed gas and the water migrated by electro-dragging will reach a balance in the membrane and determine the resistance of PEMFC, and thus affect the performance of PEMFC. Normally, the PEMFC performance strongly depends on the relative humidity of the feed gas, and the performance decreases at lower humidity as a result of lower proton conductivity of the membrane. In this paper, we proposed to …

Lithium Air Batteries: Non-Aqueous And Hybrid Systems, Sheng-Fu Tong, Ping He, Xue-Ping Zhang, Shi-Yong Zhao, Hao-Shen Zhou

Journal of Electrochemistry

Developing energy storage devices and new materials, which match the requirements in electric vehicles (EVs) and hybrid electric vehicles (HEVs), is an effective way to balance the contradiction between the social development and the shortage of fossil energy and environment pollution. Rechargeable lithium-air (Li-air) batteries consisting of Li and oxygen as the anodic and cathodic reactants, respectively, have attracted much attention during the past decade due to their high theoretical specific energy. According to work conditions, the most studied types of Li-air batteries are non-aqueous, hybrid, and solid state electrolyte Li-air batteries. Challenges still exist in cathodes, anodes, electrolytes and …

Preparation Of Zro2-Doped Nb/Pbo2 Electrode And Electrocatalytic Performance Of Methyl Orange Degradation, Li Zhang, Wen-Yan Dong, Tai-Lai Yang, Zhen-Hai Liang

Journal of Electrochemistry

The zirconium oxide (ZrO₂)-doped niobium based lead oxide (Nb/PbO₂) electrode was prepared by electrodeposition. The microstructures and electrochemical properties of Nb/ZrO₂+PbO₂ electrode were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), linear sweep voltammetry, electrochemical impedance spectroscopy and cyclic voltammotry. In addition, the Nb/PbO₂ electrode was used as an anode for the electrochemical degradation of methyl orange (MO). Results revealed that the ZrO₂ doping made the Nb/PbO2 electrode surface denser and rougher with smaller sized crystal particles, which increased the specific surface area and enhanced the electrocatalytic activity of the …

Electrolytes For Lithium And Lithium-Ion Batteries, Zong-Rang Zhang

Journal of Electrochemistry

This is an up-to-date book published by Springer last year and focuses on the field of the electrolytes for lithium and lithium-ion batteries. A brief introduction and review of this book are given in this paper. The main contents of this book are introduced briefly in the order of ten different chapters along with a short review of recent progress in those fields.

Time-Variant Load Models Of Electric Vehicle Chargers, Nicole P. Zimmerman

Dissertations and Theses

In power distribution system planning, it is essential to understand the impacts that electric vehicles (EVs), and the non-linear, time-variant loading profiles associated with their charging units, may have on power distribution networks. This research presents a design methodology for the creation of both analytical and behavioral models for EV charging units within a VHDL-AMS simulation environment.

Voltage and current data collected from Electric Avenue, located on the Portland State University campus, were used to create harmonic profiles of the EV charging units at the site. From these profiles, generalized models for both single-phase (Level 2) and three-phase (Level 3) …

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …

Enterprise Smart Outlet, David Faltmier, Matthew Mcgill, Luke Stencel

Electrical Engineering

The purpose of our senior project, Enterprise Smart Outlet, is to create an electrical outlet which will allow enterprise users to monitor and change their power consumption habits on a large scale. The initial goal of this project is to allow consumers to see their power consumption per outlet in real time, and then using that information conform their future habits to help them conserve electrical energy, and more importantly, money. Three requirements for our project to meet our initial goal are, the outlet will work in a standard electrical outlet and be completely compatible with current electrical standards, the …

Department Of Energy Solar Decathlon 2015, Dante C. Carrillo, Dion A. Celebrado, Jenna I. Denhaan, Christian F. Ferrer, Simon D. Hauser, Audrey L. Rempher, Joseph H. Rohrer, Casey S. Smith

Electrical Engineering

The goal of the Department of Energy (DOE) Solar Decathlon 2015 project is to design, build, and operate a zero-net energy solar-photovoltaic (solar-PV) powered residence. It is an international competition taking place in the fall of 2015 in Irvine, California. The design needs to be attractive, energy-efficient, innovative, and affordable. The Cal Poly team includes students from a variety of majors, including Architecture, Mechanical Engineering, Electrical Engineering, and many more. The different disciplines need to work together to create a functional and cohesive design. For our senior project, we have designed the electrical systems in the home, including the power, …

Design Of A High Powered Led Driver, Omar Renteria

Electrical Engineering

Research has shown that LED lighting products have greater energy efficiency, longer lifespans, and lower heat outputs than compared with traditional lighting technologies. An estimated growth of 45 percent per year through 2019 for the LED lighting market should provide a wider variety of LED related products to consumers. The goal of this project; to create a driving circuit that powers a set of high powered LEDs. The implementation of LEDs significantly reduces the power consumption in comparison with other types of light such as incandescent bulbs or CFLs, therefore saving the consumer money.

Current Protection For The Energy Harvesting From Exercise Machines (Ehfem) Project, Colton Crivelli

Electrical Engineering

The Energy Harvesting from Exercise Machines (EHFEM) project intends to create an exercise machine that recycles the energy expended by an athlete operating the machine by sending it to the electric grid. The work done by the user goes through a DC-DC converter and an inverter in order to prepare it for delivery to the grid. A protection circuit ensures that the inverter does not try to pull too much current from the DC-DC converter. The project implements a current protection system that ensures the system doesn’t experience an overcurrent condition.

The Dc House Project: Electrical System Design & Construction, John Bradley

Electrical Engineering

This project entails the design and assembly of the photovoltaic system, switchboard panel enclosure, and battery enclosure for the DC House’s main electrical system. The intended purpose of this project is to provide the electrical framework necessary for future students to easily modify and add to this rendition of the DC House. The principle design implements a variety of renewable energy sources, however this senior project only uses solar power in order to maintain a manageable scope. Each of these renewable energy sources are stepped down to a voltage of 24V and input to a Multi Input Single Output DC …

The Zephyr Charge: A Wind-Powered Usb Charger, James Dean Carson, John Pina Lopez Iii

Electrical Engineering

The Zephyr Charge project is to design and build a cell phone charger using a small wind turbine generator that can be useful to the fishermen community, namely fishermen of third world countries. The generator will output to USB for ease of charging capability. The size of the whole system should be light enough to move around, and the turbine itself will be mountable onto an edge of a wall. The goal of this project is to design and build a compact and easy to use cell phone charger, which is also efficient.

In order to be a practical product, …

Design Of A Multiple Input Single Output Dc-Dc Converter For The Dc House Project, Chad Santos, Siby James

Electrical Engineering

This senior project report describes the design and further development of the MISO (multiple input, single output) circuit. The MISO circuit harnesses power from four separate renewable energy sources (hydro, solar, wind and man) and converts it into a single DC output voltage. Though this circuit has been initially designed and tested in previous years, it was only developed enough to use as a test circuit. Further implementation will allow for the MISO to be available in a more practical setting. Professor Taufik will then take the newly designed MISO circuit to implement in a house in Indonesia.

Power Supply For Driving High Power Leds With Wireless Control, Joshua C. Avery

Computer Engineering

This project is the design of a power supply for driving high power light emitting diodes (LEDs) with wireless control. The project is divided into two sections, the power supply for driving the LED lights, and the wireless control and fan power supply.