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Density functional theory calculation for the next generation secondary batteries

Speaker

Dr. Yong Youn, Senior Researcher, Korea Institute of Energy Research

Education

- 2013-2018   Ph.D. in Materials Science and Engineering, Seoul National University

                  Thesis advisor: Prof. Seungwu Han

                  Thesis title: Computational identification of p-type transparent semiconductors

- 2012-2014   M.S. in Materials Science and Engineering, Seoul National University

                  Thesis advisor: Prof. Seungwu Han

                  Thesis title: Development of an efficient method to generate amorphous structures based on local geometry

- 2007-2012   Bachelor of Materials Science and Engineering, Seoul National University

* PROFESSIONAL EXPERIENCE

- 04/2021-present    Senior researcher, Institute: Korea Institute of Energy Research

- 09/2019-03/2021   Postdoctoral researcher, Institute: National Institute for Materials Science (NIMS) (Advisor: Dr. Yoshitaka Tateyama)

| Date | Friday, November 5th, 2021

| Time | 10:00~

| Venue | 온라인 (https://snu-ac-kr.zoom.us/j/81219554480?pwd=VXVsZzgzMnp0ZlpLWmV3OVhLZDNEUT09) 

Abstract

Li-ion batteries have been widely used due to their lightweight, high energy density and rechargeability. Despite the outstanding advantages of Li-ion batteries, their high price and limited quantities make it difficult to cope with the explosively increased usage for the energy storage. In this respect, some alternative metal elements such as Na, K and Mg have been researched to be used in rechargeable battery fields. In this talk, I will introduce two of our works on density functional theory (DFT) calculation for the next generation rechargeable batteries.

First topic is regarding the hard carbon anode for Na-ion batteries. Development of high-energy-density anode is crucial for practical application of Na-ion battery as a post Li-ion battery. Hard carbon, though a promising anode candidate, still has bottlenecks of insufficient capacity and unclear microscopic picture. Usage of the micropore has been recently discussed, however, the underlying sodiation mechanism is still controversial. To clarify the mechanism, we examined the origin for the high-capacity sodiation of hard carbon via DFT calculation and demonstrated that nanometer-size Na clusters with 3-6 layers are energetically stable between two sheets of graphene, a model micropore, in addition to the adsorption and intercalation mechanisms.

In the next part, I will describe the work for the electrolytes of the Mg-ion batteries. Mg-ion rechargeable batteries have attracted attention as the next generation battery due to the various advantages such as the high abundance, low cost, high volumetric capacity and high safety. However, the lack of highly efficient electrolytes has impeded the realization of the Mg-ion battery. In order to accelerate the development of high-performance electrolytes, we elucidated the configurational, electronic, and dynamical properties of several fluorinated alkoxyborate or alkoxyaluminate-based electrolytes, an emerging class of the potential electrolyte materials.

| Host | Prof. Seungwu Han (02-880-1714)