Recent Research Interests

Hydrogen Embrittlement

Zr-based cladding for the spent nuclear fuel serves as the last protection layer for the high-level nuclear waste. Hydrogen embrittlement in nuclear fuel cladding is one critical mechanism for the cladding’s mechanical failure, causing brittle fracture and cracks. Understanding the thermodynamics, kinetics and fatigue/creep behavior of Zr-based cladding is critical for the spent nuclear fuel disposal, and we seek to establish a fundamental understanding based on experimental and computational tools. The effect of the light element interstitials including H, O or C on the alloy and hydride phases are to be explored. 

Molten Salt Chemistry 

Recent interest in molten salt reactors and molten salt-based thermal storage calls for better structural materials against molten salt corrosion and detailed understanding of the molten salt-metal interaction. We seek to study the fundamental aspects of the molten salt-metal interaction and molten salt chemistry itself via electrochemical methods and computational/machine learning methods. Grain boundaries and microstructural effects are of special interest.  

[References]
43. Physical properties of KCl-UCl3 molten salts as potential fuels for molten salt reactors
Journal of Nuclear Materials 2023 577 154329
H. Kim^†, C. Kwon^†, S. Ham, J. Lee, S.J. Kim*, S. Kim*

Stress and Temperture Impact on Electrochemistry

Stress couples to various aspects of electrochemical reactions, including the electrochemical potential, diffusion, composition or phase behavior. This fundamental aspect of materials science has various exciting features that we can employ into device concepts. Some examples include the electrochemically driven mechanical energy harvesters or electrochemical actuators. However, understanding such behavior has been difficult to establish. We attempt to study the fundamental materials science aspects of stress-electrochemistry coupling by 1) designing novel device concepts and 2) in situ characterization techniques.

[References]
27. Strong Stress-Composition Coupling in Lithium Alloy Nanoparticles
Nature Communications 2019 10 3428
H.K. Seo, J.Y. Park, J.H. Chang, K.S. Dae, M.-S. Noh, S.S. Kim, C.-Y. Kang, K. Zhao, S. Kim*, J. Yuk*

21. Li Alloy-based Non-Volatile Actuators
Nano Energy 2019 57 653-659
M.-S. Noh, H. Lee, Y.G. Song, I. Jung, R. Ning, S.W. Paek, H.-C. Song, S.-H. Baek, C.-Y. Kang*, S. Kim*

5. Electrochemically driven Mechanical Energy Harvesting
Nature Communications 2016 7 10146
S. Kim, S.J. Choi, K. Zhao, H. Yang, G. Gobbi, S. Zhang, J. Li*