Faculty

Ju Li

 

Disciplines

Research

Overcoming Timescale Challenges in Atomistic Simulations

Atomistic and first-principles modeling, which describe the world as assembly of atoms and electrons, provide the most fundamental answer to problems of materials. However, they also suffer the most severe timescale limitations.  For instance, in molecular dynamics (MD) simulations, in order to resolve atomic vibrations, the integration time step is limited to hundredth of a picosecond, and therefore the simulation duration is limited to sub-microsecond due to computational cost. Although a nanosecond simulation is often enough (surprisingly) for many physical and chemical properties, it is usually insufficient for predicting microstructural evolution and thermo-mechanical properties of materials. There is clearly a timescale barrier between science-based simulations and practical demands such as understanding plant reliability and nuclear waste storage.

Energy Storage and Conversion

A close coupling of in situ experimental observations with modeling has proven to be a powerful paradigm for understanding materials behavior [Science 330 (2010) 1515; Nature 463 (2010) 335].  Based on such fundamental understandings, we are developing novel nanostructured materials for energy storage and conversion, in applications such as batteries, fuel cells and hydrogen-embrittlement resistant steels.

Materials in Extreme Environments and Far from Equilibrium

Materials in nuclear fission and fusion applications often involve exceptionally high stresses, high temperature and high radiation flux. We study the effects of radiation on microstructure and thermal, electrical and mass transport properties. The concept of fictive temperature(s) that characterize out-of-equilibrium materials is an intriguing statistical mechanics problem, with applications in glasses and even in soft biological materials.

Selected Publications

J. Li, S. Sarkar, W. T. Cox, T. J. Lenosky, E. Bitzek and Y.Z. Wang, “Diffusive molecular dynamics and its application to nanoindentation and sintering,'' Phys. Rev. B 84 (2011) 054103.

J.S. Qi, J.Y. Huang, J. Feng, D.N. Shi and J. Li, “The Possibility of Chemically Inert, Graphene-Based All-Carbon Electronic Devices with 0.8 eV Gap,'' ACS Nano 5 (2011) 3475-3482.

J. Y. Huang, L. Zhong, C. M. Wang, J. P. Sullivan, W. Xu, L. Q. Zhang, S. X. Mao, N. S. Hudak, X. H. Liu, A. Subramanian, H. Y. Fan, L. Qi, A. Kushima and J. Li, “In situ observation of the electrochemical lithiation of a single SnO2 nanowire electrode,'' Science 330 (2010) 1515-1520..

S. Hara and J. Li, “Adaptive strain-boost hyperdynamics simulations of stress-driven atomic processes,'' Phys. Rev. B 82 (2010) 184114.

T. Zhu and J. Li, “Ultra-strength materials,'' Progress in Materials Science 55 (2010) 710-757.

Q. Yu, Z.-W. Shan, J. Li, X.X. Huang, L. Xiao, J. Sun and E. Ma, “Strong crystal size effect on deformation twinning,'' Nature 463 (2010) 335-338.

J. Y. Huang, F. Ding, B. I. Yakobson, P. Lu, L. Qi and J. Li, “In situ observation of graphene sublimation and multi-layer edge reconstructions,'' PNAS 106 (2009) 10103-10108.

Related News

Strain can alter materials’ properties
New field of "strain engineering" could open up areas of materials research with many potential applications, according to new research from Professor Ju Li and his colleague Professor Bilge Yildiz
April 2, 2014
Prof. Li presents NSE seminar, Nov. 21
Nanoscale electrochemical tests: in situ TEM experiments and modeling Professor Ju Li, Nuclear Science and Engineering and Materials Science and Engineering, MIT
November 16, 2011
Prof. Li straddles nuclear engineering and materials science
Newly appointed Battelle Energy Alliance Professor of Nuclear Science and Engineering and Professor of Materials Science and Engineering Ju Li applies his groundbreaking research into atomic-scale
October 12, 2011