Speakers

Understanding the Anomalously High Capacity of Electrode Materials for Next Generation Li Batteries

윤원섭
Won-Sub Yoon
Sungkyunkwan University
Nov. 30 16:30~17:00

Abstract

Recently, various novel mesoporous metal oxides have been widely investigated as electrode materials for LIBs. These studies have opened up a possibility for the development of anode materials with significantly improved Li-storage performance. The mesostructure can be readily designed to exhibit hierarchical mesoporosity to promote facile and fast Li-ion diffusion, and a uniform framework thickness of 10nm or less so that there is a reduced diffusion length for solid-state Li transport. Synthesized ordered mesoporous SnO2 showed a reversible capacity of about 1000 mAhg-1, which is higher than the predicted value based on the alloying reaction mechanism of Sn, formed from conversion reaction of SnO2 with Li. Additionally, we have found that the mesoporous MoO2 anode presented here gives a high Li-storage capacity (1,814 mAhg-1 at first cycle and 1,607mAhg-1 after 50 cycles) as well, which is much higher than its theoretical capacity based on the conversion reaction of MoO2 with Li (838mAhg-1). As aforementioned, several research groups have newly proposed Li-storage mechanisms; however, this extra Li-storage mechanism of transition metal oxide is still unclear, suggesting that the high capacity of the mesoporous MoO2 in the present work probably results from a different Li-storage mechanism than those previously reported.

The results from mesoporous SnO2 and MoO2 anode materials further provide a more complete understanding of possible Li-storage mechanisms for transition metal oxides, and thus make possible the further advancement of ultrahigh capacity anode materials for Li rechargeable batteries. More detailed discussion will be presented at the time of meeting.

 

Biography

Won-Sub Yoon is a professor in the Department of Energy Science at Sungkyunkwan University (SKKU). He received his Ph.D. in materials science and engineering from Yonsei University, Korea. He worked at Brookhaven National Laboratory as a principal investigator and Kookmin University as a faculty member. His research is focused on electrode materials and the structural properties for energy conversion and storage systems including rechargeable batteries, fuel cells, and supercapacitors. He has over twenty years of experience in rechargeable batteries. He used to serve as chair of Battery Division (2 years), The Korean Electrochemical Society (KECS) and Director (5 years), Center for Energy Human Resources Development.

 

Education

  • 1997.03-2001.02, Yonsei University, Seoul, Korea
    – Ph. D. in Metallurgical Engineering
    – Thesis title: A study on the capacity fading and cyclability enhancement of LiAlyCo1-yO2 cathode for Li rechargeable batteries
    – Thesis advisor: Prof. Kwang-Bum Kim
  • 1995.03-1997.02, Yonsei University, Seoul, Korea
    – M. S. in Metallurgical Engineering
    – Thesis title: A study on the superactivation behaviors of Al-Ga
    – alloys in alkaline solution
    – Thesis advisor: Prof. Kwang-Bum Kim
  • 1988.03-1995.02, Yonsei University, Seoul, Korea
    – B.S. in Metallurgical Engineering

 

Professional Career

  • 2016.03-Present, Professor
    – Department of Energy Science, Sungkyunkwan University
  • 2011.09-2016.02, Associate Professor
    – Department of Energy Science, Sungkyunkwan University
  • 2008.03-2011.08, Assistant/Associate Professor
    – School of Advanced materials Engineering, Kookmin University
  • 2006.10-2008.03, Associate Scientist
    – Job: In-situ analysis of catalyst for fuel cell and electrode materials for Li battery using synchrotron-based X-ray techniques. Developing new electrode materials for rechargeable lithium batteries and fuel cells. Chemistry Department, Brookhaven National Laboratory
    NY11973, USA
  • 2004.04-2006.09, Assistant Scientist
    – Job: In-situ analysis of catalyst for fuel cell and electrode materials for Li battery using synchrotron-based X-ray techniques. Developing new electrode materials for rechargeable lithium batteries and fuel cells.
    – Chemistry Department, Brookhaven National Laboratory
    NY11973, USA

 

Awards and Honors

  • 2012, “Battery research award” by Minister of the Korean government Ministry of Knowledge Economy (MKE)
  • 2008, Selected as Top 25 hottest articles in Electrochemistry Communications
  • 2008-2009, Selected as The Marquis Who’s Who in Science and Engineering
  • Invited and co-chaired in the Electrochemical Society Meetings
  • 2006, Featured in BNL webpage for Li rechargeable battery research using synchrotron-based X-ray
  • Has been serving as reviewer in “Electrochimica Acta”, “Journal of Power Sources”, “Physical Review B”, “Chemistry of Materials”, “Journal of the Electrochemical Society” and “Electrochemical and Solid-State Letters”
  • Has been reviewing DOE’s Small Business Innovation Research (SBIR)/Small Business technology transfer (STTR) proposal
  • 2003, Selected as Science Highlight Story in National Synchrotron Light Source (NSLS) Activity Report