Scientific Program

Conference Series Ltd invites all the participants across the globe to attend 14th International Conference on Energy and Materials Research Dallas, Texas, USA.

Day 2 :

Keynote Forum

Carter S Haines

University of Texas at Dallas, USA

Keynote: Generating electricity from yarn twist

Time : 09:30-10:00

Conference Series Energy Materials 2017 International Conference Keynote Speaker Carter S Haines photo
Biography:

Carter S Haines is an Associate Research Professor at the University of Texas at Dallas’ Alan G. MacDiarmid Nanotech Institute. His research focuses on using carbon nanomaterials and polymer yarns to develop new types of energy harvesters, energy storage materials, and artifi cial muscles. Applications for these multifunctional fibers include smart yarns and textiles that store and generate energy, and that actuate to respond to their environment.

Abstract:

Mechanical energy harvesters are needed for diverse applications, including self-powered wireless sensors, structural and human health monitoring systems, and the extraction of energy from ocean waves. Harvesters based on rubber dielectrics that change capacitance when strained can directly convert deformation into electricity, but typically require high voltages and additional circuitry to apply a bias voltage. In contrast, we present a new type of carbon nanotube yarn harvester that converts tensile or torsional mechanical energy into electrical energy, without requiring these large voltages or an external bias. When deformed in an electrochemical cell, these nanotube yarn harvesters produce electricity by changing double-layer capacitance. Stretching coiled yarn generated 250 watts per kilogram of peak electrical power when cycled up to 30 hertz, as well as up to 41.2 joules per kilogram of electrical energy per mechanical cycle, normalized to harvester yarn weight. We have demonstrated using these harvesters in the ocean to harvest wave energy, sewing harvester yarns into textiles for use as selfpowered respiration sensors, and using a single 19.6 mg yarn to power a light-emitting diode and to charge a storage capacitor.

Keynote Forum

Na Li

University of Texas at Dallas, USA

Keynote: Spinning nanotubes into artificial muscles, super capacitors and energy harvesters

Time : 10:00-10:30

Conference Series Energy Materials 2017 International Conference Keynote Speaker Na Li photo
Biography:

Na Li has received her BS and PhD degree in Chemistry from Nankai University in China. She currently works as a Research Scientist in the Alan G MacDiarmid NanoTech Institute, at the University of Texas at Dallas. She has her expertise in fabrication and processing of nanomaterials, especially into multifunctional yarns. Her study mainly focuses on high performance artifi cial muscle fi bers, novel energy conversion and harvesting solutions, bio-mimetic soft robotics, and stimuli-responsive textiles.

Abstract:

Humans long ago discovered the basic secrets of yarn spinning and used them to create strong yarns from short natural fibers such as wool and cotton. In recent decades, the discovery of carbon nanotubes has enabled us to downsize this process by spinning fibers 10,000 times smaller in diameter than a human hair. Such simple twisting processes can increase the strength of carbon nanotube aerogel sheets over 1,000 times by densely pack the nanotubes into yarns. The small diameter of the nanotubes (~10 nm) within these thermally- and electrically-conducting sheets enables nanotube yarns to be highly-flexible. Twisting functional guest materials together with nanotube sheets can form knottable, weavable, and knittable supercapacitor yarns that facilitate ultrafast charge and discharge cycles, binder free lithium ion battery yarns, biofuel cell yarn electrodes, and high critical-current-density superconducting yarns. Spinning also causes strong mechanical coupling between yarn twist and the guest material within a yarn, due to helical alignment of the high-stiffness nanotubes. This unusual property has allowed us to make stimuli-responsive yarns that act as artificial muscles. Such muscles can actuate in response to electricity, chemical pickup, light absorption or heat, and provide greater force than natural skeletal muscle. These multifunctional yarns seek to enable a new era of smart textiles that can store energy, sense and actuate to adjust the comfort of a wearer, and harvest energy from human motion.

Break: Refreshment Break 10:30-10:50 @ Atrium
  • Speaker Sessions: Advanced Energy Materials, Advanced Nanomaterials & Hydrogen Energy
Location: Allen
Speaker

Chair

Bahman Zohuri

University of New Mexico, USA

Speaker

Co-Chair

Jin Chul Park

Chung-Ang University, Korea

Session Introduction

Husam N Alshareef

King Abdullah University of Science & Technology (KAUST),Saudi Arabia

Title: Two dimensional nanomaterial’s for energy storage applications

Time : 12:10-12:35

Speaker
Biography:

Husam Alshareef is a Professor of Materials Science & Engineering at King Abdullah University of Science & Technology (KAUST) in Saudi Arabia. He holds a PhD from North Carolina State University, USA. His group at KAUST develops semiconductor nanomaterials for electronics and energy applications. The author of 330 scientific articles, he has nearly 75 issued patent, and has given hundreds of international invited and contributed presentations.

Abstract:

Fast electron and ion transport are important design parameters for nanostructured electrodes for energy storage applications, including batteries and super capacitors. Typically, fast electron transport has been achieved by incorporating conducting additives such as carbon black with the active electrode materials that have low conductivity. Such approach can indeed enhance the overall electronic conductivity of the electrode material in electrochemical energy storage devices. However, fast ion transport cannot be achieved using the same approach. Instead, controlling the dimensionality of the active electrode material has emerged as a powerful method to enhance ion diff usion within the electrode materials in electrochemical storage systems. 2D materials off er a large number of advantages as active electrode materials in batteries and super capacitors. This because the 2D morphology increases the surface area and reduces the ion diff usion distance, effects that can improve electrolyte access to as many active materials atoms as possible, and improve the ion diff usion kinetics. 2D electrode materials offer many other advantages in electrochemical systems. In addition, the 2D material morphology can minimize the volume changes associated with conversion and alloying mobile ion battery electrodes. In some applications, such as catalysis, the 2D materials edge defects can serve as active nucleation sites for catalytic reactions and have been reported to achieve impressive performance compared to commercial catalysts. Until recently, graphene and reduced graphene oxide have been the dominant 2D materials evaluated for energy storage applications. However, many more 2D compounds have emerged and now compete with graphene in performance. Such materials include transition metal chalcogenides (e.g., MoS2 and WS2), oxides (e.g., VO2 and SnO), transition metal carbides or MXenes (e.g., Ti3C2 and Ti2C), and even polymeric and metal organic frameworks. The common factor between all these compounds is their 2D morphology, which provides extreme surface area to volume ratio, which enhances the overall performance of these electrode materials for energy applications. In this presentation, we review recent progress in using 2D nanomaterials for electrochemical energy storage applications, with special focus on super capacitors and Na/Li ion batteries.

Lei Zhao

Baker Hughes, A GE Company, USA

Title: Advanced carbon composite material for heavy oil and geothermal energy recovery

Time : 12:35-13:00

Speaker
Biography:

Dr. Lei Zhao is a Lead Scientist from Baker Hughes, A GE Company. His working areas include high temperature seal, Nano composites, nanofabrication, as well as smart materials. Before joining Baker Hughes in 2013, he did his postdoc research on metal nanocomposite in Argonne National Laboratory, Chicago, Illinois and PhD study on polymer nanocomposite in Georgia Tech. He has published over 30 papers in journals including Nature Nanotechnology, advanced materials, Angewandte Chemie, etc., and filed over 30 patent applications in area of energy materials.

Abstract:

Lack of high temperature elastic seals has been the bottleneck for the energy industry to economically and safely explore geothermal energy and heavy oils. The reserve of heavy oil is three times the total amount of conventional oil and gas combined, and resource of geothermal energy is almost unlimited. In these applications, hot fluids are required to be safely sealed in an enclosed system, the temperature of which could easily reach to 750°F (399°C) and above, and the seal material also has to survive the extremely corrosive downhole environment. Traditionally, elastomers are the materials chosen for downhole
sealing applications. But this type of organic material is prone to decompose when temperatures approach 600°F (316°C) and even lower in wellbore fluids. Metal to metal sealing systems may have the temperature tolerance, but lacks enough elasticity to provide reliable seal performance in downhole conditions. This presentation will introduce a newly developed elastic carbon composite (ECC), which is a highly engineered material with both mechanical and chemical properties readily tuned for specifi c applications. Tests show that the elastic carbon composite material has excellent thermal stability over 1000°F (538°C) and strong corrosion resistant to extremely corrosive environment including concentrated acid. In this presentation, we will also discuss the performance of the elastic carbon composite as a high temperature seal, and provide some exemplary industrial applications in unconventional energy recovery, including packing elements, O rings, and chemical injection valves seals.

Break: Panel Discussion 13:00-13:10 | Group Photo @ Allen | Lunch Break 13:10-14:10 @ Atrium
Speaker
Biography:

Thirumany Sritharan is a Professor at the School of Materials Science and Engineering, NTU, Singapore. His expertise is in multiferroic materials, thin films and solar energy harvesting. He is currently the main PI in NTU for the multi-million $ CREATE program between NTU-Singapore, University of California, Berkeley and NUS, Singapore. This program is fully funded by the National Research Foundation of Singapore under their CREATE umbrella funding program. It is on the topic of Sustainable Energy and has a total of about 60 researchers from both Singapore and Berkeley. Prior to this, he has worked on multiferroic materials with special attention BiFeO3 epitaxial thin films and on various thin film and interfacial problems in microelectronic circuits. He has obtained his PhD from The University of Sheffield, UK and worked at The University of Melbourne and Comalco Research Centre, Melbourne before joining NTU Singapore.

Abstract:

The monoclinic scheelite BiVO4 is recognized as one of the promising candidate materials for photoanode because of its 9.1% theoretical solar-to-hydrogen efficiency. While signifi cant research effort has been devoted to improving the photoelectrochemical cell performance of this material, they have mainly been in small anode areas. This talk will give the methodologies employed to produce a scaled-up 5x5 cm2 photoanode and give results of its performance in a large photoelectrochemical cell to split water. Multiple modifi cations were made, by systematic experimental evaluations, to enhance the performance of the anode. These are: use of an under layer, an over layer of co-catalyst, and doping the BiVO4 with Mo. These will be described. An adverse effect of area was noted in our studies which we call the “areal effect”. The photocurrent density steadily decreased with increase of illumination area. Evidence to specifically verify the areal effect were obtained experimentally and will be discussed. This is the first documented evidence for this effect. Understanding the reasons for the areal effect is indispensable for the development of large scale PEC devices for water splitting. Preliminary information on the stability of the large area anode in the electrolyte will also be shown and discussed.

Speaker
Biography:

Kamal Choudhary is a Post-doctoral Researcher at National Institute of Standards and Technology. His current area of research is database development and management for atomistic calculation using classical force-field, quantum density functional theory and machine learning through JARVIS (Joint Automated Repository for Various Integrated Simulations) project.

Abstract:

We introduce a simple criterion to identify two-dimensional (2D) materials based on the comparison between experimental lattice constants and lattice constants mainly obtained from Materials-Project (MP) density functional theory (DFT) calculation repository. Specifically, if the relative difference between the two lattice constants for a specific material is greater than or equal to 5%, we predict them to be good candidates for 2D materials. We have predicted at least 1356 such 2D materials. For all the systems satisfying our criterion, we manually create single layer systems and calculate their energetics, structural, electronic, and elastic properties for both the bulk and the single layer cases. Currently the database consists of 1012 bulk and 430 single layer materials, of which 371 systems are common to bulk and single layer. The rest of calculations are underway. To validate our criterion, we calculated the exfoliation energy of the suggested layered materials, and we found that in 88.9% of the cases the currently accepted criterion for exfoliation was satisfied. Also, using molybdenum telluride as a test case, we performed X-ray diffraction and Raman scattering experiments to benchmark our calculations and understand their applicability and limitations.

Speaker
Biography:

Francis D’Souza Received Ph. D. from the Indian Institute of Science, Bangalore, India in 1992, and post-doctoral studies at the University of Houston and University of Dijon, France. He was a Professor of Chemistry at Wichita State University, Wichita, KS from 1994 to 2011, and joined the faculty of University of North Texas in 2011. He is part of UNT’s Bio Nano Photonics research cluster. Francis D'Souza's research covers wide areas of chemistry, nanophotonics and materials science. Principal research interests include chemistry and supramolecular chemistry of porphyrins and carbon nanomaterials, light energy harvesting, photo electrochemistry and photovoltaics, ultrafast spectroscopy, electrochemical and photochemical sensors and catalysts, fluorescent chemosensors and biosensors, conducting nanocomposite hybrid materials for energy storage and conversion.

Abstract:

To tackle the ever increasing energy demand of modern society and avoid environmental pollution caused by burning fossil fuels, solar energy is perhaps the most attractive, renewable, clean and inexhaustible energy source. Therefore, efficient capture and conversion of solar energy into chemical energy and electricity by utilizing molecular systems that follow the concept artificial photosynthesis has witnessed rapid growth during recent years. In the design, multi-modular donor-acceptor systems capable of wide-band light capture for maximum utilization of sun light, and subsequently perform the process of photo induced electron transfer leading to long-lived charge separated states of sufficient stored energy are key factors. The stored energy in the electron transfer products will be subsequently utilized for light-to-electricity and light-to-fuel production. The talk will present recent developments in our laboratory on the research topic of building supramolecular systems capable of visible-near infrared light capture, and transporting the captured light to the donor-acceptor site for carrying out successive light induced electron transfer resulting in high potential charge separated states in solution and electrode surfaces. Further, utilization of surface modified artificial photosynthetic systems for solar fuel production will also be highlighted.

Jin Chul Park

Chung-Ang Université, South Korea

Title: Window ventilation system with artificial intelligence

Time : 15:25-15:50

Speaker
Biography:

Jin Chul Park is an architectural engineering Professor and has been working in Chung-Ang University since 2004. He had been postdoctoral work from 2001 to 2002 in University of Michigan (Ann Arbor, USA). In association activities, he is the president of the KGBC (Korea Green Building Council) and the vice president of AIK(Architectural Institute of Korea). Also he has experienced an Editor of JABBE (Journal of Asian Architecture and Building Engineering) from 2010 to 2012. He has been interested in indoor air quality, energy saving in buildings. In his recent research, he is carrying out research to reduce greenhouse gas and save energy and to create indoor environment. He has authored or coauthored 50 fully-refereed technical articles during 10 years.

Abstract:

Since we humans spend more than 85% of the day indoors, the management of indoor air quality is very important for health. Particularly, most indoor dust particles are generated indoors, but they are also introduced into the room due to external environmental pollution. Therefore, in recent research, dust particles are seriously threatening the health of occupants. There are many ways to control the dust particles in the room, but ventilation is most effective. However, ventilation is only eff ective on the condition that the outside air is clean. That is, when the outside air is contaminated, it is necessary to purify the outside air. Therefore, this study proposes a ventilation system using windows that can control indoor and outdoor air together. In particular, it is a ventilation system that takes into account various new factors such as artificial intelligent, IoT, and behavior patterns of occupants, and indoor / outdoor and temperature / humidity. Also, in order to control polluted indoor / outdoor air, a window ventilation system with an air filter is provided. And the window ventilation system has the advantage of saving building energy by being connected with artificial intelligence. Therefore, the artificial intelligent window ventilation system will provide a comfort environment for occupants and contribute to the improvement of indoor air quality.

Break: Refreshment Break 15:50-16:10 @ Atrium

Mohamed Mahmoud Hassan

QC In-charge at Arabian International Company for steel

Title: Weldability of dissimilar joint of Steel/ 1100 Aluminum alloy and its quality

Time : 11:40-12:10

Speaker
Biography:

Mohamed Mahmoud is a native of Khartoum City and he lives in Saudi Arabia, Riyadh. Mohamed enrolled at Sudan University for science and technology in May 2007. He was an active student there, pursuing his interests in student events, drama, and football while living at home and helping to run the family’s store. Mohamed won a scholarship to attend Osmania University’s science school in July 2013, where he was leader of the foreigner Student Association. He graduated in June 2015. His primary research interests are in the field of welding. Specifically, he is interested weldabilty of dissimilar material as steel and aluminum and study of the joint quality .

Abstract:

Joining of dissimilar materials has found a wide use especially in power plants, nuclear reactors, chemical and gas industries; this will produce a desirable properties and weight reduction. However, the welding of dissimilar metal faces big challenges due to the difference in the thermo mechanical, chemical and physical properties of the two metals to be joined following one welding procedure.
Unsymmetrical deformation has been observed with respect to the plane of the joint interface; the formation of intermetallic compound may increase the sensitivity for the cracks and reduce the ductility as well increasing the susceptibility to corrosion. Tungsten Inert Gas TIG welding is one of the possible processes in order to join dissimilar metals such as steel and aluminum alloys by conducting self-brazing technique due to its possibility to produce partial penetration weld in steel sheet. Currently, welding-brazing of steel to aluminum alloys has become a point of research method in heterogeneous metals joining, which includes ARC welding brazing and laser welding-brazing with the filler metal.
Dissimilar weld is mainly required to form different chemical and physical properties of metals; this is to reduce the material cost, increase the performance and minimize the susceptibility to failure and maintenance. Nowadays there is a high demand of the use of welding techniques to join dissimilar metals, mainly ferrous with non-ferrous.

  • Speaker Sessions: Materials Science and Engineering & Nanotechnology in Materials Research
Location: Allen
Speaker

Chair

Hyoyoung Lee

Sungkyunkwan University, Korea

Session Introduction

Bahman Zohuri

University of New Mexico, Mexico

Title: Why we need nuclear power plants?

Time : 16:10-16:35

Speaker
Biography:

Bahman Zohuri is currently at the University of New Mexico as Associate Research Professor and Consultant at Sandia National Lab as well as Galaxy Advanced Engineering, Inc. a consulting company that he stared himself in 1991 when he left both semiconductor and defense industries after many years working as a chief scientist. After graduating from University of Illinois in field of Physics and Applied Mathematics, he joined Westinghouse Electric Corporation where he performed thermal hydraulic analysis and natural circulation for Inherent Shutdown Heat Removal System (ISHRS) in the core of a Liquid Metal Fast Breeder Reactor (LMFBR) as a secondary fully inherent shut system for secondary loop heat exchange. All these designs were, used for Nuclear Safety and Reliability Engineering for Self-Actuated Shutdown System. He designed the Mercury Heat Pipe and Electromagnetic Pumps for Large Pool Concepts of LMFBR for heat rejection purpose for this reactor around 1978 where he received a patent for it. He then was, transferred to defense division of Westinghouse later, where he was responsible for the dynamic analysis and method of launch and handling of MX missile out of canister. He has later on joined Lockheed and Rockwell International working on Satellite system for SDI as well as working and developing sensor system on board for remote sensing as well GIS. He later on was a consultant at Sandia National Laboratory after leaving United States Navy. Dr. Zohuri earned his first Bachelor's in Applied Mathematics and his second one in Physics along with his Master’s degrees in Physics from the University of Illinois and his second Master degree in Mechanical Engineering as well as his Doctorate in Nuclear Engineering from University of New Mexico. He has been, awarded three patents, and has published 32 textbooks and numerous other journal publications. Recently he has been involved with Cloud Computation, Data warehousing, and Data Mining using Fuzzy and Boolean logic.

Abstract:

Some scientists are calling the nuclear power plants source of energy as 100 percent renewable energy and off course environmentalists arguably are saying that is wrong approach, just because in the core of these plants there exist Uranium or Plutonium as fuel when we are talking about fission type nuclear power plants that they exist in grid today and producing electricity to the net. However, on the other side of spectrum where, researchers and scientist at national laboratories and universities around the globe that are working toward fusion program to achieve a breakeven are passionately argue that nuclear power plants of fusion type are totally clean so long as the source of energy come in form of two hydrogen isotopes such as Deuterium (D) and Tritium (T) as source of fusion reaction and driving energy from it. This is a dream that is too far away from reality of today's need and demand for electricity, yet is not out of scope of near future. Physics of Plasma for driving energy via Inertial Confinement Fusion (ICF) or Magnetic Confinement Fusion (MCF) agree with such innovative approaches.

Speaker
Biography:

Sunghwan Lee is currently an Assistant Professor at Baylor University since fall 2015. He earned a Doctoral degree in Materials Science at Brown University where he focused on transparent oxide semiconductors and their high mobility thin film transistor (TFT) devices. He has spent two and a half years for his Postdoctoral research in Chemical Engineering at MIT in Materials Science/Applied Physics at Harvard University where he was working on various projects in the field of transparent flexible electronics and energy conversion devices such as TFTs, solar cells, and fuel cells based on the materials of CVD-grown conjugated polymers and oxide ion conductors.

Abstract:

Oxy-apatites based on rare earth silicates (A10x(SiO4)6O2±x, A=rare earth cation) are of increasing interest for solid oxide fuel cell (SOFC) application due to the high conductivity at moderate temperatures (<1000 K). Here, we report on the intermediate-temperature synthesis (973 K) of thin film oxy-apatites and high total conductivity of the cerium silicate-based apatites at temperatures <750 K: the Ce4.67 (SiO4)3O-based apatites (~80 nm-thick) were synthesized at 973 K at very low oxygen partial pressure (p(O2)<10-17 atm) and the incorporation of ZnO into the cerium silicate system leads to the high
total conductivity of ~0.05-0.2 S/cm. The formation of oxy-apatites was identified by in-situ conductivity measurements as a function of p(O2), x-ray diff raction analysis and x-ray photoelectron spectroscopy. In particular, the in-situ conductivity measurements confi rm that the dominant conduction mechanisms of this class of materials are mainly dependent on oxygen interstitials. Since these materials are prepared at low p(O2) and are stable in reducing atmospheres, Ce4.67(SiO4)3O-based thin film apatites exhibiting high conductivity are of relevance as anodes for intermediate temperature thin film SOFC application. In order to evaluate the performance of the apatite anode in SOFC devices, thin film apatites were grown on Sc-stabilized ZrO2/LSCF electrolyte/cathode substrates. Bilayer anode of apatite/Pt and Ni- apatite composite anode were also utilized in the identical electrolyte/cathode system and the performance were compared. The noteworthy SOFC performance (e.g., peak power density of ~100 mW/cm2 at 748K) and superior stability were observed in Ni-apatite SOFCs due to higher catalytic activity and low contact resistance at the electrolyte/anode interface compared to those with a single layer apatite anode and bilayers of apatite/Pt anode. Th e present study demonstrating intermediate temperature synthesis of Ce4.67 (SiO4)3O-based
oxy-apatites and their high conductivity may signifi cantly contribute to the field of intermediate temperature thin fi lm SOFC applications.

Rahim Munir

King Abdullah University of Science & Technology, Saudi Arabia

Title: Science communication: Effective use of social media for scientists

Time : 17:00-17:25

Speaker
Biography:

Rahim Munir is a doctoral candidate at King Abdullah University of Science and Technology (KAUST) and affiliated with the KAUST Solar Center (KSC), where he works on understanding the structure-properties-performance relationship for perovskite solar cells. He completed his MSc degree from the Korea Advanced Institute of Science and Technology (KAIST). He leads a team of scientists from KAUST to perform x-ray based experiments at Cornell High Energy Synchrotron Source (CHESS). Munir is an active member of the Materials Research Society (MRS) and played major leading roles in the MRS-KAUST Student Chapter. He publishes articles on his personal blog and is a volunteer science writer for MRS Bulletin. He has given several invited talks about leadership and communication skills and has encouraged students of Saudi universities to pursue science and engineering as their career. Recently, he organized the “Academic Writing” symposia during the 2016 MRS Fall Meeting in Boston. In his free time, he enjoys reading Oriental philosophy.

Abstract:

The paucity of scientists engaging in communicative activities has created a vacuum of knowledge in the age of information. Social media provides the platform to share the discoveries and inventions at the lab scale. Promulgating the research publication is through social media is becoming a routine for the journals. In this talk, I will show the jaw-dropping statistics of people using social media. I will share the key resources and freeware which can be used in order to promote your work with only the basics of graphic designing. Blog and personal website help to create a portfolio for an individual and the lab. I will share the examples of personal websites of scientists promoting their work. We are just beginning to explore the power of social media at this stage; it has a long way to go. Joining the social media revolution at the right time will provide the ample opportunity to stand out as a researcher.

Biography:

Belqasem Aljafari has completed his MS at the age of 29 years from Northern Illinois University school of engineerin. He is pursuing his education by studying
currently the PhD degree schoold of engineering.

Abstract:

Electrical energy storage devices such as batteries and supercapacitors are essential elements in many portable and wearable electronics. However, conventional energy storage devices are usually bulky and solid, not being very suitable for applications that need mechanical flexibility. In this work, we have presented a fully flexible supercapacitor device made from two carbon nanotube (CNT) paper based electrodes with a layer of a gel type electrolyte between the electrodes. The electrodes were fabricated by spreading a suspension solution of CNT over a piece of Xerox paper and dry the paper in a vacuum oven. The gel was made by adding polyvinyl alcohol (PVA) to an acid solution and stir the solution for a few hours. Despite the simple method of fabrication, the fabricated devices presented relatively high capacitances. Devices were made with two different gel electrolytes, using H2SO4 and H3PO4 acids. Electrochemical study of the devices showed 39.39 mF and 30.44 mF capacitances for the H2SO4-PVA and H3PO4-PVA electrolytes, respectively. Also, the devices presented series resistances about 30 Ω which is low enough for many small electronic applications. The device characteristics were also measured while bending them under various curvatures. Less than 15% change in capacitance was observed when devices were bent up to 1.6 cm-1 curvature. However, the capacitance was return to the original value aft er relaxing the device. The excellent electrochemical properties and the mechanically stability of the devices are promising for low-cost electronic applications.

  • Speaker Sessions: Solar Energy Materials, Batteries and Energy Materials & Biomaterials and Surface Science Engineering
Location: Allen
Speaker

Chair

Muge Acik

Argonne National Laboratory, USA

Speaker

Co-Chair

Servet Turan

Anadolu University, Turkey

Session Introduction

Wonbong Choi

University of North Texas, USA

Title: Carbon nanomaterials for advanced rechargeable batteries

Time : 10:50-11:15

Speaker
Biography:

Wonbong Choi is a tenured, Full Professor in the Department of Materials Science and Engineering and Mechanical and Energy Engineering at University of North Texas, Denton. He has obtained his PhD in Materials Science and Engineering from the North Carolina State University (NCSU) in 1997. After his PhD, he has worked in the industry research laboratory as a Senior Researcher and Project Manager at Samsung (SAIT). He was a Leading Scientist in the carbon nanotubes for Tera-level nano electronics device project. He has been awarded the prestigious Materials Research Society (MRS) Medal for 2006. He has awarded MRS Fellow in 2009. He has successfully conducted numerous granted projects funded by AFOSR, DARPA, NSF, SRC, DOE and Samsung. He is the author/co-author of over 80 patents, one book (“GRAPHENE” CRC Press 2011), 10 book chapters, over 240 publications, which includes 140 peer-reviewed journal articles and over 70 conference proceedings. His research articles have been cited over 10,000 times with H-index of 51 (Google Scholar). He serves as a reviewer for more than 20 international journals and serves on the Editorial Board of five journals.

Abstract:

Next-generation energy storage devices, such as Li-ion batteries (LIBs) and Li-sulfur batteries (LiS), demand high energy, power and better safety. Conventional graphite anode falls short of fulfilling all these necessities. Carbon nanostructural materials (graphene and carbon nanotubes) have gained the spotlight as promising anode materials for energy storage; they exhibit unique physico-chemical properties such as large surface area, short Li+ ion diff usion length, and high electrical conductivity, in addition to their long-term stability. Among all published literatures in Li-ion battery, nanostructured carbon materials occupy ~70%. Such an impressive figure signifies high interest and promising future of this class of materials in energy storage devices and compels us to consider the involved issues deeply. Carbon-nanostructured materials have issues with low areal and volumetric densities for the practical applications in electric vehicles, portable electronics, and power grid systems, which demand higher energy and power densities. One approach to overcoming these issues is to design and apply a three-dimensional (3D) electrode accommodating a larger loading amount of active anode materials while facilitating Li+ ion diffusion. Furthermore, 3D nanocarbon frameworks can impart a conducting pathway and structural buff er to high-capacity non-carbon nanomaterials, which results in enhanced Li+ ion storage capacity. In this presentation, the current status of the design and fabrication of 3D carbon nanostructures will be reviewed. Our recent progress on 3D carbon nanomaterials for LIBs and Li-S batteries will be presented. Finally, the superior performance of 3D carbon nanotube-sulfur will be presented along with its mechanistic analysis.

Muge Acik

Argonne National Laboratory, USA

Title: Alcohol-catalyzed growth of lead halide perovskites for energy harvesting

Time : 11:15-11:40

Speaker
Biography:

Muge Acik is currently an Argonne Scholar-Named Fellow at Argonne National Laboratory. She obtained a B.S. in chemistry from Izmir Institute of Technology (Turkey), a M.S. in materials science and nanoengineering from Sabanci University (Turkey), and a Ph.D. in materials science and engineering from the University of Texas at Dallas. Prior to Argonne, she also worked for Texas Instruments Inc. as a Process Development Engineer for memory device production. Her work as the PI covers the analysis of surfaces and interfaces of the graphene-based thin films using in situ spectroscopy, and the discovery of new perovskite growth methods for energy harvesting and nanoelectronics. Indeed, she is the recipient of 2015 Distinguished Joseph Katz Postdoctoral Fellowship, 2011 MRS Graduate Student Silver Award, and 2011 MRS Best Poster Award.

Abstract:

Methyl ammonium lead trihalide (MAPbX3) perovskites have great potential as light harvesters for energy harvesting due to their unique optical and electronic properties. The conventional growth techniques apply spin-coated precursors on a substrate followed by annealing for the processing of the lead halide perovskites; however, use of toxic solvents and high temperature hinder device stability and performance. To avoid annealing processes, the solution-based methods have been developed. I will introduce a new one-step solution technique to facilitate in situ crystal formation of methyl ammonium lead bromide and methyl ammonium lead chloride perovskites at the micron (~1-10 μm) to nano scale (< 500 nm) (Fig.1). As a substrate-free approach, the crystal pre-growth allows crystallization in alcohols (methanol, ethanol, 2-propanol, 1-butanol, and 2-butanol) at room temperature followed by a direct precipitation of the perovskite material for a large-area deposition. This room-temperature process able technique, however, differs from the in situ growth of methyl ammonium lead iodide crystals in alcohols that eliminates treatment at the boiling point of the alcohols. The high-energy synchrotron XRD, wide angle x-ray scattering (WAXS), Fourier transform infrared (FTIR) in transmission/reflection geometry (ATR, % R), UV-Vis-NIR (% R), micro Raman spectroscopy, and the solid state 1H, 13C, and 207Pb –MAS NMR are performed for characterization. The perovskite crystals show improvement in air/moisture for their chemical stability (<1.5 months). The thermo gravimetric analysis and in situ techniques also determine their thermal stability (~150-300°C). The poor yield of methyl ammonium lead iodide in toluene confirms that the alcohols catalyze the growth process through a substitutional reaction mechanism. Indeed, the theoretical calculations reveal that the growth of the perovskites in alcohols is exothermic. These materials will eventually find their use in applications of photovoltaics,3,4 photo detectors, optical-thermal sensors, light emitting diodes, light-emitting field-eff ect transistors, lasers, solar fuels, batteries, super capacitors, radiation detectors, data storage, hydrogen fuel cells, and photo catalysis.

Speaker
Biography:

Alexander Kobryn has his expertise in predictive and descriptive modeling of equilibrium and time-dependent non-equilibrium phenomena in soft condensed matter systems such as molecular and macromolecular liquids and solutions, electrolytes and polyelectrolytes, gels and polymer blends, with the use of methods from statistical physics, theoretical physics, and theoretical and computational chemistry to research quantum and classical systems on multiple time and length scales, in nanoconfined geometries, and in nanoporous media. Successful applications include, in particular, polymer design rules for self-assembly of functionalized ionomers, explanation of the gelation mechanism and prefiguring of the gelation ability of multifunctional oligomeric electrolyte gelators, modeling of the active layer nanomorphology and dynamics of polymer blends that are building blocks for inexpensive organic and organic-metallic-halide solar panels, controlled fluid flow in MEMS and NEMS with CFD coupled to molecular properties of fluid and channel materials, etc.

Abstract:

Both descriptive and predictive modeling of structural properties of blends of PCBM or organic-inorganic hybrid perovskites of the type CH3NH3PbX3 (X=Cl, Br, I) with P3HT, P3BT or some squaraine SQ dye sensitizer, including adsorption on TiO2 clusters having rutile (110) surface, is presented with the use of a methodology that allows computing the microscopic structure of blends on the nanometer scale and getting insight on miscibility of its components at various thermodynamic conditions. The methodology is based on the integral equation theory of molecular liquids in the reference interaction site representation/model (RISM) and uses the universal force field. Input parameters for RISM, such as optimized molecular geometries and charge distribution of interaction sites, are derived with the use of the density functional theory methods. To compare the diff usivity of the PCBM in binary blends with P3HT and P3BT, respectively, the study is complemented with MD simulation. A remarkably good agreement with available experimental data and results of alternative modeling/simulation is observed for PCBM in P3HT system. We interpret this as a step-in validation of the use of our approach for organic photovoltaic and support of its results for new systems that do not have reference data for comparison or calibration. For the less studied P3BT, our results show that expectations about its performance in binary blends with PCBM may be overestimated, as it does not demonstrate the required level of miscibility and short-range structural organization. The performance of P3BT with perovskites, however, seems as expected. The calculated nanoscale morphologies of blends of P3HT, P3BT or SQ with perovskites, including adsorption on TiO2, are all new and serve as an instrument in rational design of organic/hybrid photovoltaics. They are used in collaboration with experts who make prototypes or devices for practical applications.

Speaker
Biography:

Servet Turan is a Professor at Materials Science and Engineering at the Anadolu University in Eskisehir, Turkey. He has received his BSc in 1988 at Istanbul Technical University and MSc in 1990 at Leeds University whereas, he finished his PhD degree at Cambridge University in 1995. Since then, he has been at Anadolu University. His research interests include the lithium-ion batteries, thermoelectric materials, advanced ceramics and electron microscopy based techniques for characterisation of all sorts of materials including in-situ heating.

Abstract:

Nowadays, garnet type solid electrolytes are extensively studied electrolytes for Li-ion batteries along with other types of electrolytes such as Perovskite, LISICON and LIPON. Cubic Li7La3Zr2O12 (LLZO) phase is relatively recently found composition that shows satisfying ionic conductivity. However, the room temperature stable form of LLZO is tetragonal and either adding stabilizers or increasing sintering temperature have been employed to stabilize cubic phase at room temperature. Recently, it was found that the cubic phase stabilization temperature could be lowered by using solution-based synthesis. However, there is a lack of knowledge on how the anions acting for the stabilization of cubic LLZO. In this work, the effect of (NO3)2- and Cl- ions on the cubic phase stabilization was discussed through the sol-gel synthesis. Zr (NO3)2 and ZrOCl2 were selected as (NO3)2- and Cl- anion sources, respectively. 20 mole % Al content as cubic stabilizer was kept constant. After calcination, as-synthesized powders were sintered by using both conventional powder bed sintering and spark plasma sintering (SPS). Crystal structures of calcined powders and sintered pellets were measured by using X-Ray Diff raction (XRD). Combined TGA-FTIR was used to analyze exhaust gases at ppm level. Grain size as well as particle morphology were evaluated by using scanning electron microscope (SEM). True densities and ionic conductivities of sintered pellets were measured by using Archimedes method and AC impedance spectroscopy, respectively. Results showed that high purity cubic LLZO phase in a powder form was obtained after calcination at 1000°C by using ZrOCl2 precursor whereas larger size (NO3)2- anions inhibit the cubic phase stabilization. Since there were (NO3)2- anions in the solution that came from LiNO3 and La(NO3)3, it can be concluded that a limited (NO3)2- anion concentration was needed to stabilize cubic phase.

Speaker
Biography:

Rahim Munir is a doctoral candidate at King Abdullah University of Science and Technology (KAUST) and affiliated with the KAUST Solar Center (KSC), where he works on understanding the structure-properties-performance relationship for perovskite solar cells. He completed his MSc degree from the Korea Advanced Institute of Science and Technology (KAIST). He leads a team of scientists from KAUST to perform x-ray based experiments at Cornell High Energy Synchrotron Source (CHESS). Munir is an active member of the Materials Research Society (MRS) and played major leading roles in the MRS KAUST Student Chapter. He publishes articles on his personal blog and is a volunteer science writer for MRS Bulletin. He has given several invited talks about leadership and communication skills and has encouraged students of Saudi universities to pursue science and engineering as their career. Recently, he organized the “Academic Writing” symposia during the 2016 MRS Fall Meeting in Boston. In his free time, he enjoys reading Oriental philosophy.

Abstract:

Organic-inorganic hybrid lead halide perovskite semiconductors have attracted a great deal of attention because of their remarkable optoelectronic properties which make them potentially suitable as active materials in photovoltaics, light emission, and photodetection. The key reason for its popularity is that it can yield good semiconductor properties despite being solution processed in ambient conditions and requires no vacuum or excessive heating. To date, the most efficient perovskite solar cells have been fabricated using spin coating, for which several ink and solvent engineering methods have been developed and perfected. However, this is a wasteful process which cannot be easily scaled up to continuous large area fabrication, where existing solvent engineering methods, such as anti-solvent dripping, are also unlikely to work. Here we compare the ink solidification and film formation mechanisms of CH3NH3PbI3 in DMF by spin-coating versus blade-coating using in-situ time-resolved optical metrology and x-ray scattering. We show signifi cant differences in the process kinetics and formation of complex intermediate phases between the two processes at room and intermediate temperatures. To overcome these challenges in the context of blade coating, the sample is heated during deposition. We observe high-quality film formation for T > 100oC, namely in conditions which inhibit the formation of the crystalline intermediate complex phases. In doing so, we achieve fast and direct formation of the perovskite phase with solar cells yielding PCE > 17%.

Break: Lunch Break 12:55-13:55 @ Atrium
Speaker
Biography:

Dr. Shih-Feng Chou is an Assistant Professor in the Department of Mechanical Engineering at The University of Texas at Tyler. He completed his PhD from Auburn University in 2011 followed by working as a research associate at Dartmouth College from 2012 to 2013 and a senior fellow at University of Washington from 2014 to 2016. He has expertise in fabrication of electrospun nanofi bers and evaluation of their mechanical and pharmaceutical properties. His goal is to inform the field on how to decouple mechanical performance and drug release behaviors of implantable biomaterials.

Abstract:

Electrospun Nano fibers are advantageous in drug loading efficiency with the ability to tune release rates based on polymer compositions. As a result, the mechanical behaviors of the Nano fibers may be signifi cantly aff ected by polymer compositions and drug loading. However, effects of drug loading on the mechanical properties and release behaviors of fi ber-based delivery system have not been fully investigated. Here, we studied the mechanical behaviors and pharmaceutical performance of blend polycaprolactone (PCL) and poly(D,L-lactic-co-glycolic) acid (PLGA) Nano fibers at various blend ratios with drug loading up to 40 wt.%. Results from uniaxial tensile tests suggested that Nano fibers made from various PCL/PLGA blends and drug loadings exhibited strong drug-polymer interactions. Average Young’s moduli and tensile strength of blank PCL/PLGA Nano fibers gradually increased with increasing PLGA contents in the blend Nano fibers. However, TFV loaded Nano fibers revealed a different trend in mechanical properties as comparing to blank Nano fibers, indicating the eff ects of drug-polymer interactions. In particular, PCL/PLGA 20/80 Nano fi bers received minimal changes in mechanical properties due to off setting effects in drug-polymer interactions at drug loading up to 40 wt.%. Tensile samples collected from the release media at predetermined time points showed signifi cant decreases in average Young’s modulus and tensile strength as compared to the blank Nano fibers. The additional loss of mechanical properties was associated with drug release and biodegradation of polymer matrix. Interestingly, TFV release rates increased in prestretched Nano fibers. Mechanical assessments on drug partition in PCL/PLGA Nano fibers suggested higher drug content in the PCL phase than in the PLGA phase. This study contributes signifi cantly to the understanding of drug-polymer interactions in electrospun drug-eluting Nano fibers and provides important information for implantable therapeutic biomaterials in future clinical applications.

Speaker
Biography:

Bheeshma P Singh is working as SERB Indo-USA Post-doctoral fellow since January 2017 in Dept. of Chemistry at University at Buffalo, SUNY in the group of Prof. Paras N Prasad. His expertise mainly includes the nanomaterials synthesis and its bimodal applications such as efficient NIR to NIR biomarkers, ferro fluid based hybrid nanostructure for hyperthermia in cancer therapy, LEDs and all inorganic perovskite quantum dots for display applications.

Abstract:

CaWO4:Tm3+, Yb3+, Li+ nano-phosphors with intense NIR to NIR (excitation by 980 nm, emission at ~800 nm) up conversion were synthesized by a facile polyol route. The nanoparticles were of the order of ~20 to 60 nm. The XRD patterns confirmed a single-phase tetragonal scheelite structure having space group I41/a, irrespective of doping of small amounts of RE3+ and alkali ions. The incorporation of Li+ ions altered the crystal field symmetry around the Tm3+ ions, which increased the f–f transition probabilities of the RE3+ ions, and thus increased the up conversion intensities. Compared with CaWO4:Tm3+, Yb3+, the NIR to NIR up conversion emission intensity of 10 mol% Li+ substituted CaWO4:Tm3+, Yb3+ nanocrystals increased by 20-fold and can be pumped by ~1mW power 980 CW laser. The brightest CaWO4:Tm3+, Yb3+, Li+ nano-phosphor was applied for non-invasively visualizing the tumors in nude mice and successfully detected deep tumors in the thigh muscles. Results were based on oxide based UCNPs used for in vivo NIR-to-NIR bio-imaging which opens the window of achieving improved features using non-fl uoride based UCNPs for bio-imaging.

Biography:

Sam Solomon is working as an Associate Professor in the Department of Physics, Mar Ivanios College, and Thiruvananthapuram, India. He has MSc in Physics and PhD in microwave materials. He received the Junior Research Fellowship from the Council of Scientifi c and Industrial Research - India in 1992, Dr. S Vasudev award for the best major research project from the Council of Science and Technology in 2008 and the Post-doctoral Research Award from the University Grants Commission in 2009. He was selected by the University of Kerala for the Commonwealth Fellowship in 2005. He has 83 papers in reputed journals and more than 50 conference presentations. He supervised six PhD and is a reviewer of Elsevier and Springer publications.

Abstract:

Solid oxide fuel cells (SOFCs) are a class of fuel cells characterized by the use of a solid material as the electrolyte. SOFCs use a solid electrolyte to conduct negative oxygen ions from the cathode to the anode. The electrochemical oxidation of the oxygen ions with hydrogen or carbon monoxide thus occurs on the anode side. The purpose of this presentation is to discuss the synthesis and characterization methods of nanomaterials for electrolytes in solid oxide fuel cells.

Synthesis: One of the efficient methods for the synthesis of nano particles is the modified combustion technique. In this method stoichiometric amounts of chemicals are made in to a solution and heated. The solution boils and undergoes dehydration followed by decomposition leading to a smooth deflation producing foam. On persistent heating, the foam gets auto-ignited due to self-propagating combustion, giving a voluminous fluffy nanopowder. The obtained powder is annealed in oxygen atmosphere below 700oC to eliminate the trace amount of organic impurity that may remain in the sample.

Characterization: Structure of the as-prepared powder can be identifi ed by the powder X-ray diff raction (XRD) technique and the particle size using transmission electron microscopy. The powder can be pressed into disc pellets of thickness 2 mm using a hydraulic press with a pressure of 100 MPa, and then sintered at optimized temperatures. The surface morphology of the sample is analyzed using scanning electron microscopy (SEM). The impedance spectroscopic study is carried out by making the pellet in the form of a disc capacitor.

Conclusion & Significance: The impedance spectroscopic studies establish the feasibility of the materials to use as an electrolyte in SOFCs.

Clederson Paduani

Universidad Federal de Santa Catarina, Brazil

Title: Nanostructured catalyzing agents for hydrogen desorption from light metal hydrides

Time : 15:10-15:35

Speaker
Biography:

Clederson Paduani is currently working as an Associate Professor at Universidade Federal de Santa Catarina in Florianópolis, SC, Brazil. He has been working with DFT calculations in clusters, solids and nanostructures, after completing his Post-doctoral degree at CNRS, Grenoble, UCSC, CA, VCU, VA, and UPenn, PA.

Abstract:

Hydrogen, as an energy carrier, is nowadays considered as one of the best alternatives for mobile and stationary power sources for both propulsion and fuel cells. However, one of the major drawbacks of this technology is the problem of storing hydrogen safely, since in liquid and gas form, this demands high pressure or cryogenic reservoirs. An alternative is the use of solid state hydrogen storage, wherein the light metal hydrides represent a promising solution. However, since these are usually highly stable compounds, where the hydrogen atoms are held by strong covalent bonds, high temperatures are required for the hydrogen desorption. In order to surpass this difficulty the addition of catalysts has been considered, such as transition metals and nanostructured agents. In this study first, principle calculations based on density functional theory are performed to investigate the role of catalysts in dehydrogenation from clusters of light metal hydrides. It is shown that the addition of titanium and nanostructured carbonaceous catalysts contributes for a significant gain in the energy cost for hydrogen desorption from the metal hydrides. The combined addition of titanium with carbon fullerenes is even more beneficial for decreasing the energy cost of dehydrogenation. This effect is confirmed for different metal hydrides like alanates and boranates. For example, the calculated energy cost for H-removal from the magnesium boro-hydride is 4.18 eV, which decreases to 4.08 eV upon the addition of the fullerene C60, and to 3.32 eV in the presence of C67. The combined addition of Ti and these fullerenes lead to a decrease of energy cost for the H-removal to 4.04 eV and 2.78 eV, respectively. The energetics of dehydrogenation is also investigated in super-halogen clusters of light metal hydrides, and the results show that the hydrogen release is substantially less energy demanding in these highly reactive moieties. Results of van der waals-corrected DFT calculations show a rather significant gain in the energy cost for H desorption with the addition boron-doped fullerene catalysts. In the source of this effect is the disturbance introduced in the distribution of bonding charge upon the hybridization of states in the interplay between the hydride cluster and the fullerene with a consequent weakening of the hydrogen bonds, leading therein to an enhanced kinetics for the hydrogen release.

Break: Panel Discussion 15:35-15:45 | Refreshment Break 15:45-16:05 @ Atrium
Speaker
Biography:

Chika Anthony Okonkwo has his expertise in products development and production with acquired knowledge in an interrelated electromechanical technology and chemical, and bio chemical engineering. This current cost-effective and high specifi c capacitance product enhancement is supplementary contribution out of numerous conceptualized, designed, and fabricated products that solve problems in energy conversion/storage and materials processing. These achievements accounted for his years of experience in research institute (National Agency for Science and Engineering Infrastructures NASENI Abuja Nigeria) and doctoral research in chemical and biochemical engineering Xiamen University China. Still, he is very optimistic for functional energy material from biomasses for high efficiency of solar cells and high specific capacitance of supercapacitor.

Abstract:

Statement of the Problem: High ions storage target for supercapacitors still suffer from limited mesopores which hampers accommodation of most ionic sizes and also slows competitive/huge commercialization of electrochemical double layer capacitors especially where high power and rapid responses are necessary. Mesopores as indispensable factor of high ions storage, attract many diverse materials in researches over decades for this reason to improve specific capacitance and directly obtain high energy and power densities. Carbonaceous materials or its composites have shown that due to inherent/intrinsic adjustable property, mesopores are high predictable in carbon materials especially in variable shape/structural forms which usually improve by activation with potassium hydroxide (KOH). However, dual shape/structure by simple cost-effective preparation method (salt encapsulated sand template) has not been previously studied. This study centers on describing the interstice/ intramesopores dual form in a systematic steps sand induces surface roughness which metamorphous into honeycomb-shape/flakes carbon.

Methodology & Th eoretical Orientation: Typical acid anhydrous decomposition was employed to produce silicon carbide particles from the sand to induce rough surface on carbon flakes during the castor seed shell break down. The residual acid in the carbon was deprotonated by hydrothermal process to prevent acid salt formation in the presence of potassium hydroxide during activation process and also to reduce the formation of water molecules that may inhibit anhydrous KOH activation of the carbon. Imperative porosity characterization, structural/functional group investigation, and fundamental shape morphology were conducted to compare the two major samples. Conventional graphite symmetric electrodes were prepared as electrochemical double layer capacitors in 6 M KOH electrolyte.

Findings: The interstice / intra-mesopores mixture consists of high specific surface area of fl akes and honeycomb-shape carbon required to boast the mesopores porosity. N2 adsorption-desorption curve shows type IV isotherm to confirm the presence of mesopores, wherefore related dV/dD particle distribution shows predominating mesopores range (2–50 nm) inset. Energy transmittance across the sample molecules shows effect of dual molecular related shapes of carbon consistently across the FTIR spectra. Oxygen-containing functional groups content satisfi es the conditions for surface wettability and enhancement of ions transfer rate as represented in XPS chemical state. As supercapacitors electrode, the superior sample exhibited high specific capacitance (481 Fg-1) in 6 M KOH as electrolyte. Almost no decay occurred aft er charging/discharging test of 15000 cycles and the capacitance retention remains 96 %.

Conclusion & signifi cance: Indeed the degree of improvement in this study really shows that ions storage largely depends on mesopores to make high specific capacitance in the right context of better carbonaceous materials. This template decomposition of castor seed shell is quite promising, however more organic carbonaceous or composites are necessarily good approach to achieving the expectancy of ultra-high specifi c capacitance of supercapacitors.

Mazharul M Islam

Universität Bonn, Germany

Title: Ti and Si based anodes for Li ion batteries: Insights from theory

Time : 16:30-16:55

Speaker
Biography:

Dr. Mazharul M Islam has been working as senior research fellow at the Mulliken Center for Theoretical Chemistry of the University of Bonn Germany. He has got the expertise on theoretical modeling using various first principles DFT approaches. His interest of research activities has covered a wide variety of areas such as the ion conductivity in solid state materials having applications in green energy sources, the investigation of photocatalytic activities of TiO2 due to its various industrial applications, the modeling of basic mechanisms of corrosion processes of metallic materials during their applications in construction, power generation etc, and the characterization of mesoporous oxide supported metal oxide catalysts having applications in industries. He was awarded with couple of honors and awards, various funding and huge number of collaborations in his career. He has published 3 scholarly books, 2 scholarly book chapters and 53 articles in peer reviewed journals so far.

Abstract:

Li-ion batteries (LIBs) have a great combination of high energy and power density capacities, which has made the LIB technology as the prime choice for portable electronics, power tools, and hybrid/full electric vehicles. The electrochemical performance of LIBs strongly depends on the electrode properties. The conventional Li-ion batteries use Li metal and carbonbased materials, typically graphite, as anode materials. However their applications are limited due to safety issues caused by dendrites formation. Therefore alternative anode materials are employed for the next generation LIBs which cover titanium oxide based materials as well as alloying/de-alloying materials with Si. In the present contribution, the stoichiometric and defect properties of lithium titanim oxides and various LixSiy compounds are investigated theoretically using the first-principles density functional theory (DFT) methods. We have considered two diff erent Li2Ti3O7 structures: ramsdellite and layered types. In ramsdellite Li2Ti3O7 Li+ can migrate along the ‘one dimensional channel’ or along crystallographic ac plane. Our calculated EA for Li+ diffusion in the one dimensional channel ranges from 0.20−0.92 eV and that in the ac plane ranges from 0.30−0.85 eV. However due to the large energy difference between the initial and final stages for Li diffusion in the case of ac plane shows that these pathways are kinetically prohibited. Therefore, the ramsdellite Li2Ti3O7 is a qasi-one-dimensional ion conductor. In the layered Li2Ti3O7, Li migrates along the crystallographic b direction by a vacant tetrahedral cite as well as along the ab plane in a direct pathway. The ab-plane migration is the most likely as it has a smaller activation barrier (0.4 eV) compared to the tetrahedral migration pathway (0.95 eV). Recent studies have provided evidence for the formation of various stable Li silicide crystalline phases such as LiSi, Li4.7Si2, Li12Si7, Li7Si3, Li13Si4, Li15Si4, and Li22Si5 during lithiation. In the present study, we have studied LiSi and Li13Si4 in order to search for a fast Li ion conductor. Our study shows that the interlayer interactions due to the van der Waals (vdW) forces play a key role for the structure and energetic properties of LixSiy materials. In case of LiSi, Li migrates to the 1st and 2nd nearest distance by a Li point defect. The activation energy for the both possible pathways range between 0.2 to 0.25 eV, indicating a very fast ion conduction in LiSi compounds. On the other hand, Li migration in Li13Si4 is slightly more complex. Li migrates either in a direct migration pathway or by a tetrahedral pathway. The activation energy for the direct migration pathway is 0.65 eV whereas that for the tetrahedral pathway is 0.75 eV. Therefore we conclude that Li13Si4 is slower ionic conductor than LiSi.

Biography:

Hussein Alrobei is a Ph.D. student under the supervision of Manoj K Ram. He has background in the fi eld of photo electrochemical, advanced materials, polymers and energy. He has been involved on photo electrochemical properties on various metal oxides, polymers and conducting polymers, and recently his patent on Nano-hybrid structured regioregular polyhexylthiophene blend films for production of photo electrochemical energy has been approved.

Abstract:

The purpose of this paper is to present a literature review of a sampling of the current available research documents that discuss experimental and potential industrial processes of producing gaseous hydrogen fuel utilizing various nanotechnology products and techniques. While the production of essentially pure hydrogen gas (H2) is not a new concept and has been used in laboratories and industry for a number of decades, the development of nanotechnology and its unique products has opened the door for an explosion of new research to establish processes for making hydrogen in ways that are much more environmentally conscious, safer, and potentially will allow production from totally renewable sources. The current and recent research includes work done producing hydrogen from a number of sources with water being the source used most. The promise of potentially producing sufficient hydrogen to meet the world energy needs using water as the source for the hydrogen and solar energy as the source of the power to fuel the production is reason enough to justify the investment in the research into this field of study. Because of the attractiveness of this approach and the significant amount of work being done with water and solar, we concentrate our review in that area. We touch upon other methods but remain with the water/solar concentration. The common theme in all the papers reviewed is the utilization of nanotechnology in all of the research looked at.