Khalil Amine is an Argonne Distinguished Fellow and leader of the Advanced Lithium Battery Technology team at the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory. He directs the research and development of advanced materials and battery systems for hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), electric vehicle (EV), satellite, military, and medical applications. Amine is also deputy director of the U.S.-China Clean Energy Research Center and an adjunct professor at Stanford University. He also holds a joint appointment as a professor at the University of Chicago.
Amine is a specialist in advanced energy storage. He co-invented lithium nickel manganese cobalt oxide (LiNiMnCoO2 or NMC) cathode technology, which has been licensed and mass-produced by BASF and Toda, among others. He has published more than 632 peer-reviewed papers in the field, which have been cited nearly 56,000 times. Amine is a six-time recipient of the R&D 100 Award, a prestigious recognition for technology innovation. He is also president of the International Meeting on Lithium Batteries, chair of the Automotive Lithium Battery Association and founder and organizer of the Advanced Lithium Battery for Automotive Application (ABAA) global conference.
In the Q&A below, Amine discusses the role that national labs can play in spurring market innovation.
Q. Some of your latest work involves new approaches to oxide cathodes, such as gradient materials and coatings. What are the potential applications of this technology?
A. My team has been working on developing advanced high-energy cathodes with a focus on reducing Co and maximizing the Ni. These types of materials however are highly reactive when operating at high voltage. To address this major issue, which compromises both the life and the safety of the battery, we have developed a series of Ni-rich full-gradient concentration NMC cathodes. In these cathodes, the concentration of Ni is gradually reduced from the center to the outer layer of the particle, while Mn is increased toward the outer layer of the particle to minimize reactivity and stabilize the cathode at high voltage.
Recently, we achieved a new breakthrough by developing a bimodal gradient cathode that has 94% Ni with a unique surface rock salt structure that significantly stabilizes the Ni-rich NMC at 4.8 V with no capacity fade after hundreds of cycles. A patent on this new material has been filed, and we are actively engaging DOE and an industrial partner to set up a collaborative program to advance this material for validation in cells designed to power electric vehicles.
The application of the gradient cathode and PEDOT coating…can find applications in consumer electronics and smart grids, where energy and safety are critical. — Khalil Amine, leader of the Advanced Lithium Battery Technology team at Argonne National Laboratory
Another approach to stabilizing the cathode at high voltage is to develop a robust protective film at the surface of the cathode. A majority of scientists in both academia and industry are focusing on the partial coating of the cathode by dispersing nano particulates of the material they selected during the coating process using a co-precipitation process. This coating is not effective when operating at voltages higher than 4.4 V. We have developed a new coating approach where we deposit a uniform PEDOT [poly(3,4-ethylene dioxythiophene)] polymer coating that is both electronically and ionically conductive using a gas phase polymerization process that covers all the exposed area of the cathode particle — both the secondary and the primary particle. This coating stabilizes the cathode at 4.6 V and prevents any oxygen release at high voltage, impacting positively both the cycling and the safety performance of the battery. This work was published in Nature Energy recently. The application of the gradient cathode and PEDOT coating is obviously to enable low-cost, long-life and safe batteries for automotive applications, but it also can find applications in consumer electronics and smart grids, where energy and safety are critical.
Q. How can scientists at national labs translate their research into technologies that drive market innovation?
A. My experience in pushing technologies invented by my team to a real application is that it is always best to explore engaging an industrial partner with whom we can collaborate closely to advance the invention and validate it with a real battery. In some cases, we leverage both DOE’s and the industrial partner’s funds to accelerate the development of the technology and enable a real-life application. In my opinion, this is by far the fastest approach to move innovation from the lab to a real-world application. The other approach that I’ve used successfully is to work very closely with Argonne’s technology transfer team to engage the potential licensee of the technology developed by my team. This requires, of course, having large personal networks. I must say that my experience working in different countries before and during my tenure at Argonne has allowed me to build a huge network of people in both academia and industry around the world. This certainly helps in promoting an innovation — either licensing or seeking funds to enable and validate the innovation — to industry for quick implementation in a real-world application.
Q. What’s the next big innovation in energy storage that can impact the world?
A. I believe that advanced lithium ion, possibly using a high ratio of Si [silicon] anode to reach ~350–400 Wh/kg, could be the next practical replacement of the existing lithium ion that powers electric vehicles today. The big innovation is a battery system that can offer at least three times the energy density of the state-of-the-art lithium-ion battery. At the moment, a big focus is on using a solid-state battery with lithium metal to achieve 500 Wh/kg. This target, although very aggressive, can provide at most twice the energy density of today’s battery. My team, in close collaboration with ANL’s Molecular Materials team [led by Larry Curtiss] is working on enabling a new lithium superoxide closed system that has the potential to offer three times the energy density of today’s lithium ion. This system consists of reacting lithium superoxide with lithium to form lithium peroxide. No gaseous oxygen is involved, in this case, and the production of the cell will be similar to that of lithium ion. Of course, if a solid-state battery is developed, it can be applied to this concept as well.
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