ABSTRACT: The continued release of more and more greenhouse gases, which have led to global warming, is a serious issue that must be resolved on the global scale. One of the reasons behind this increase in pollution is the indiscrete use of fossil fuels, which are mainly used for industrial and transportation applications. Renewable energy sources represent alternatives to fossil fuels, although they are intermittent. This emphasizes that selecting an appropriate energy storage system is very important in order to successfully utilize renewable energy. Among various energy storage technologies, using an electrochemical secondary battery is a promising method for large-scale storage of electricity due to its flexibility, high energy conversion efficiency, and simple maintenance. At this moment, in consideration of the weight, storage capability at high rates, space/size limits, and durability, rechargeable lithium-ion batteries (LIBs) are the best candidate for storing energy that is produced from renewable energy sources. Despite the success of LIBs, there has been a strong impetus to lower the material cost and increase the specific capacity of the cathodes, especially for electric vehicles (EVs), which require high specific energy density to meet the drive range requirement per single charge. In this presentation, to increase energy density of LIBs, novel Ni-rich layered cathode of concentration gradient by placing a Ni‐rich composition in the particle center and a Ni‐deficient composition at the particle surface will be introduced. Moreover, recent achievement of next‐generation batteries developed in our laboratory, such as Na‐ion battery, Li‐S, and Li‐air batteries will be presented; we developed new synthesis that produces much better Na ion insertion cathodes a highly dense spherical particle composed of a radially assembled columnar structure compared to conventional cathodes. Lithium–sulfur (Li–S) batteries have high theoretical capacities and energy densities compared to the state-of‐the‐art LIBs but the practical application of Li–S batteries is hindered by certain severe drawbacks (polysulfide dissolution and low sulfur utilization). We have deployed novel Li‐S battery including cathode and separator which can maximize the utilization of sulfur and cycling stability even at high sulfur loading. For Li‐O2 batteries, we discovered greatly increased round trip efficiency battery based on lithium superoxide redox reaction on iridium nanoparticles.
BIOGRAPHY: Yang-Kook Sun is presently professor of Energy Engineering at the Hanyang University in Seoul (South Korea). After receiving PhD degree in Chemical Engineering at the Seoul National University in 1992, he became team leader for developing molten carbonate fuel cell system at Samsung Heavy Industries. He moved to Samsung Advanced Institute of Technology in 1996, and actually contributed as team leader of the lithium polymer battery group to the commercialization of Samsung SDI' Lithium Polymer Battery, for which he received the "Grand Prize Award" from the Korea Patent Association in 1999. He has set up within 2000 and 2008 the ITRC at the Hanyang University that is one of the largest and the most internationally active research centers for battery materials. He became an active member of The Korean Academy of Science and Technology in 2007 and a Distinguished Professor at Hanyang University in 2008.
He attended international invited talks, chaired sessions, organized various conferences focusing on energy storage and, therefore, he received several awards including the Research Awards by the Energy Technology Division and the Battery Division of The Electrochemical Society (ECS) in 2007, and 2011 and 2017, R&D 100 Award by R&D Magazine in 2012, National Green Technology award by Korea Industrial Technology Association in 2012, Lithium-ion Battery award of Ministry of Trade, Industry, and Energy from Korea Battery Industry Association in 2014, Innovative Knowledge Award from Ministry of Science, ICT and Future Planning in 2015, Engineering Award from Gyeongam Foundation in 2016, and he was selected as a Highly Cited Researcher in the specific field by Clarivate Analytics in 2016 and 2017.
He succeeded in design, synthesis and structural analysis of advanced energy storage and conversion materials for application in electrochemical devices, lithium-ion, lithium-sulfur, lithium-air, and sodium-ion batteries. Among the relevant achievements, the core-shell, concentration-gradient lithium-nickel-cobalt-manganese oxide cathode designed by myself has been licensed in 2008, 2010, and 2013 by three Korean companies, undergone production for use in E-bike batteries by LG Chemical Ltd and Niro EVs of Hyundai-Kia, and recently received continuous industrial attention. This novel synthetic pathway may, indeed, lead to efficient and high energy materials for application in next generation battery for the emerging field of electric vehicles. The same approach was successfully adopted for the preparation of sodium-ion cathodes with high-capacity and prolonged cycle. Furthermore, I actually contributed to the progress of lithium-air and lithium-sulfur batteries by designing new, high performance electrodes, electrolytes and experimental setups which are presently diffused and largely adopted by the scientific community. I recently expanded the research to the high-energy lithium-metal battery.
He has several international collaborations around the world, he is author of more than 547 publications in peer-reviewed scientific journals, and 520 registered and applied patents. The interest on his achievements is demonstrated by the large number of citations (38945) leading to an h-index as high as 104 (Google Scholar, 2018).