Electrochemical Energy Systems

Abstract: Demand of batteries keeps increasing as electronic devices get widespread and fossil-based systems are being replaced by electricity-based systems. Lithium-ion battery has been considered one of the most promising power sources for mobile and transportation systems, but it faces challenging issues of high cost, low capacity (i.e. short operation hours or driving ranges), and safety issues. Therefore, it is necessary to find the break-through technologies to resolve those issues. In this talk, two promising electrochemical systems will be introduced: aluminum-air battery and multi-valent catalytic flow battery. Aluminum is cheap and abundant, benign to the environment, and stable in moisture. But, due to the problems of self-corrosion and formation of inert oxide film on the surface of aluminum during cell operation, the Al-based rechargeable battery could not reach commercialization stage. Ionic liquid which is a molten salt in liquid form at room temperature is getting intense attention recently as a promising electrolyte to resolve those issues. In this talk, discussion will be made about the effect of the oxide film on performance of the ionic-liquid based Al-air battery and how to control the film with results of research conducted in Dr. Cho’s group at Northern Illinois University (NIU) through experiment and physic-based modeling.Redox flow battery (RFB) is enjoying a renaissance with substantial achievement of research, altering it ultra-high performing and high energy dense system. And also, the excellent feature of RFB decoupling energy from power has been applied as a key design factor to overcome the challenging issues of conventional battery systems. In this talk, new promising “redox-mediated bromate based flow battery” which has theoretical energy density greater than lithium ion battery will be introduced, and characteristic “auto-accelerated” catalytic electrochemical reaction coupled with chemical reaction will be discussed in detail.

Biographical Sketch: Dr. Kyu Taek Cho is an assistant professor of mechanical engineering at Northern Illinois University, Dekalb, IL. He has around 20-year experience in the electrochemical system through works in national lab, industry, and academy. He had worked at Lawrence Berkeley National Lab as a postdoc and then a research staff before he joined NIU in 2014. He also has industrial experience as a research engineer at Hyundai Motor Company, S. Korea to develop a fuel stack for the application to vehicle. Dr. Cho has Ph.D. achieved from Pennsylvania State University under guidance of Professor Matthew Mench. Dr. Cho is a director of Electrochemical Energy Lab at NIU to conduct the fundamental research of advanced electrochemical and thermal energy systems.