Petru Andrei, Ph.D. - US grants

This Nanotechnology Undergraduate Education (NUE) in Engineering program entitled "NUE: NanoCORE (Nanotechnology Concepts, Opportunities, Research and Education)at the Florida A&M University (FAMU)-Florida State University (FSU) College of Engineering", under the direction of Dr. Ongi Englander, is designed to introduce aspects of nanoscale science and engineering into the core undergraduate curriculum beginning in the freshman year. The NanoCORE program will infuse and integrate nanoscale science and engineering (NSE) as a permanent component of the undergraduate curriculum, present multiple opportunities for undergraduate learning of concepts in NSE and create opportunities for undergraduates to pursue nanotechnology related research activities.

The Nanotechnology Undergraduate Education (NUE) in Engineering program at Florida A&M University (FAMU)-Florida State University (FSU) entitled "NUE: NanoCORE II (Nanotechnology Concepts, Opportunities, Research and Education)at the FAMU-FSU College of Engineering", under the direction of Dr. Ongi Englander, is designed to introduce aspects of nanoscale science and engineering into the core undergraduate curriculum. The NanoCORE II program will infuse and integrate nanoscale science and engineering (NSE) as a permanent component of the undergrduate curriculum, present multiple opportunities for undergraduate learning of concepts in NSE and create opportunities for undergraduates to pursue nanotechology related research activities. The NanoCORE II program builds upon the existing NUE NanoCORE program which has made a noteworthy impact on FAMU-FSU undergraduate educational content and experience since its inception in early 2009.

The broader impact of the NanoCORE II program includes the engagement and training of undergraduate students, and particularly those from traditionally under-represented groups in areas of great technological importance. Course materials developed through this project will be made widely available through web resources and presented to the local community through outreach activities. In particular, introductory nanotechnology material designed to target a wide audience will be disseminated at the National High Magnetic Field Laboratory (NHMFL) annual open house, at a Saturday children's program at a local museum, and through lectures and demonstrations presented to Tallahassee Community College, WIMSE (Women in Math, Science and Engineering) and FGAMP (Florida-Georgia Alliance for Minority Participation) college students.

Renewable sources of electric power such as wind and solar power produce output that is constantly fluctuating in time, sometimes by more than one order of magnitude within a few minutes or hours. At penetrations larger than 20%, these fluctuations require high capacity energy storage devices that are environmentally friendly, reliable, and do not compromise the security of the national electricity grid. To address this issue, the current project introduces fundamental advances in the theoretical understanding, modeling, simulation, experimental characterization and development of Lithium-air flow systems for grid applications. The proposed systems are tailored to large-scale grid applications by being cost effective and having a high energy density and long cycle life in comparison with current electrical energy storage systems used in grid applications. The proposed systems will also represent an attractive technology for building low-cost batteries for electric vehicles, by having a design that allows fast fueling by simply changing the electrolyte with pure water and replacing the anode electrode.

The goal of this proposal is to develop innovative Li-air systems that can be scaled up and used in grid applications. The energy and power ratings of the proposed systems are independently adjustable, making the proposed batteries attractive for building high-capacity and low-cost energy storage devices. The research component focuses on understanding the fundamental science and developing the technology for metal-air electrochemical systems for large and scalable energy storage applications. The novelty of the approach lies its strong emphasis on: (1) The combined theoretical-experimental investigation of the material properties and processes in Li-air flow batteries with cathodes made of layers of buckypaper with variable porosity and catalyst deposition; (2) An innovative design for Li-air flow batteries with energy densities over 250 Wh/kg, and minimum cost. The electrochemical reaction unit of the cell (which consists of the metal anode, separator and the porous cathode) is separated from the oxygen exchange and electrolyte storage units, allowing for easy transportation, installation, and scalability of the system; and (3) Computational optimization of the porosity and catalyst distributions, and experimental development of a prototype cell. The education component focuses on the development of a Virtual Battery Laboratory - a simulation package for metal-air batteries that incorporates the theoretical models into a user-friendly battery and circuit simulator. A new Graduate Certificate Program in Renewable Energy and Energy Storage Systems, primarily addressing people from the industry will be developed, and a 2-week module on the electrochemical modeling and simulation of lithium and other metal-based batteries will be incorporated into the undergraduate and graduate curricula at Florida A&M University and Florida State University.

In this project, Arizona State University, in collaboration with Morgan State University, Florida A&M University, and the University of Texas at El Paso, will evaluate the impact of a virtual tutoring system for circuit analysis. The virtual tutor focuses on introductory linear circuit analysis, a key gateway class required of students in all engineering disciplines. Personalized to handle each student's needs, the tutoring system uses a step-based approach in which the computer accepts each step of a student's work and automatically evaluates the work, providing detailed feedback. This immediate feedback helps to correct student errors early in the learning process.

This project aims to augment, optimize, disseminate, and evaluate the impact of a virtual tutoring system (Circuit Tutor) for linear circuit analysis. Compared to similar systems, the Circuit Tutor uniquely accepts and checks every step of a student's work to provide immediate, detailed feedback, thus facilitating student learning and minimizing student frustration. Offered in "open-source" mode, the tutoring system will be freely available to students all over the world. Methods of optimizing the pedagogical effectiveness of the system will be systematically explored by studying transcripts of student work and by real-time observations of students at work with Circuit Tutor. Instructors will be provided with an online dashboard to inform them about the progress of individual students and common learning difficulties. Introduction of "desirable learning difficulties" that are believed to greatly enhance long-term retention will be explored. Integration of theoretical computer-based instruction with hands-on learning will also be studied. The software will be rigorously evaluated and results widely disseminated to multiple institutions for use in their engineering courses.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Lithium ion batteries have limited energy density, and an alternative battery chemistry is needed to continue to transform the current energy landscape. Rechargeable lithium-sulfur (Li-S) batteries are among the most promising high-energy-density electrochemical devices for future energy storage applications. However, there are intrinsic limitations that potentially lower the achievable energy density of Li-S batteries. To date, performance of this battery type has been limited by capacity loss and degradation due to permanent loss of active material (sulfur) from the electrode and from reactions of the electrode with the electrolyte. To date, developers have used excess electrolyte to dilute the side reactions that occur that result in lowered performance. This project will use combined experimental and theoretical approaches to study critical issues for high-loading and high-energy Li-S batteries. Specially designed cathode structures and electrolyte configurations will be built to analyze the effects of Li polysulfide species (LiPS) solubility on cell capacity and battery specific energy. The project will yield knowledge on the operating conditions that lead to capacity loss and degradation. The project will also integrate the research outcomes into publicly available electrochemical system simulator (ESS).

The fundamental research project will focus on using combined experimental and theoretical approaches to study two critical issues for high loading and high energy Li-S batteries. The first theme includes studies of the effect of lithium polysulfide (LiPS) solubility on cell capacity. Experiments will address the creation of LiPS saturated conditions with different and well-defined initial states-of-discharge and then the characterization of Li-S cell performance under these LiPS saturated conditions. The experiments will also investigate the rate dependence of the potential reaction pathways for LiPS reduction. The second theme addresses experimental verification and theoretical modeling of solid product deposition on the cathode. Focus of this theme is on the study of the Li2S/Li2S2 deposition process using electrochemical measurement combined with material characterization methods, including transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The accompanying feasibility modeling of a Li-S battery will incorporate the experimental verified solid product deposition process, as well as the analysis of the LiPS solubility effect in the built model. The fundamental knowledge and outcomes of this project will also be incorporated into an Electrochemical Systems Simulator (ESS) which is a simulation package for electrochemical systems that incorporates the theoretical models into a user-friendly battery and circuit simulator. The ESS will be a unified framework, in which users can define their own electrochemical devices, discretize them on finite element grids, and perform one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) simulations to study the transport and predict charge and discharge curves and the electrochemical impedance spectra of the cells.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

The goal of this project, REU-RET Mega-Site: Research Experiences for Undergraduates and Teachers in Smart and Connected Cities (led by Morgan State University), is to recruit and train a diverse population of underrepresented minority students and teachers who work in minority-serving K-12 schools and community colleges - focusing on highly relevant Electrical and Computer Engineering research topics. The project involves the development of a combined Research Experiences for Undergraduates and Research Experiences for Teachers (REU-RET) Mega-Site that is centered on the following research topics that are related to Smart and Connected Cities: IoT Security, Renewable Energy, Energy Storage, Smart Grid, Human Computer Interaction, and Advanced Materials. The consortium of institutions involved in this effort are 14 Historically Black Colleges and Universities (HBCUs) and 1 Hispanic Serving Institution (HSI). The project targets lower division students who are less likely to have the opportunity to participate in research as undergraduates. Participation in this type of experience has been demonstrated to be transformative and to have the potential to increase retention and graduation rates at these institutions. RET participants will be recruited from local community colleges and high schools that serve as feeder schools to the consortium institutions.

Providing quality research experiences to an underserved group of undergraduate students and teachers will lay the foundation for positively impacting the retention and graduation of engineering students for years to come, while also increasing the number of minority students who will eventually pursue graduate degrees. In addition, the program will improve the quality of science and engineering education at local high schools and community colleges, further stimulating the interest and imagination of underrepresented minority students who might not otherwise be inclined to pursue higher education in Science, Technology, Engineering, and Mathematics (STEM) fields. The project will serve as a national model for how to broaden participation in engineering by successfully implementing multi-institution undergraduate research programs, which others can adopt/adapt and build upon. The evaluation of this effort will be conducted by the SageFox Consulting Group and the project's outcomes will be broadly disseminated through Morgan State University's website, presentations at conferences, and articles that are published in peer-reviewed journals.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.