I am the principal developer of this efficient and scalable open-source GEM software (Gene-Environment interaction analysis in Millions of samples). I am also involved in developing the statistical method. The source code can be found here. This software also supports cloud workflows. Our manuscript is also online.

The currently released GEM adopts a multi-threading application via boost thread management. GEM can also be converted to another multi-threading paradigm, i.e., OpenMP. Paralleling the most time-consuming hot spot when processing and analyzing the data sets is the main driver for choosing one multi-threading approach over the other. So, understanding your large-scale data sets is of priority. Let me know if you are interested in learning more. We can also work together to further improve GEM efficiencies in heterogeneous computing systems.

Great to see our work which reveals defect-enhanced Li surface reaction kinetics in the battery materials is published on npj Computational Materials. This is one of the representative studies utilizing the “Defect engineering” strategy for enhancing the performance of battery intercalation compounds. The existence of anti-site defects in LiFePO4 would significantly block Li diffusion along [010] while slightly increase its diffusivity along [100] and [001]. For Li intercalation in the surface-reaction-limited kinetic regime, such decreased diffusion anisotropy obviously improves phase transformation kinetics by increasing active surface area. Moreover, a more uniform reaction flux prevents the formation of current hotspots under galvanostatic (dis)charging conditions. We believe tailoring distribution and concentration of defects is a promising approach for improving the rate performance of phase-changing battery compounds.

Lithium dendrites have different growth mechanisms before and after “Sand’s Time”. They are root filamentous growth and tip branch growth, respectively. The diffusion-induced interfacial instability leads to the formation of tip branch, but little is known about the root growth mechanism of Li dendrites. In a recent study (Nature Energy 2018, 3, 227), we developed the stress-driven dendrite growth model to interpret the dendrite mitigation by electroplating on soft substrates (from Dr. Jiang’s group at ASU). The internal compressive stress of the deposited Li film is released through surface-wrinkling-formation on the soft substrate surface.

10-31-2017, HOUSTON, TX

The study on the interesting phase transition kinetics of Pb(Mg1/3Nb2/3O3)-PbTiO3 single crystal pillars with compositions around morphotropic phase boundary under mechanical and electrical stimulus is accepted by Physical Review Applied. Various mechanically reversible and irreversible domain switching states are realized. This is the second collaborative paper that utilizes my thermodynamic model (phase-field simulations) of Pb(Mg1/3Nb2/3O3)-PbTiO3 and in-situ TEM expertise from the University of Sydney (Prof. Xiaozhou Liao and Dr. Zibin Chen). These two papers provide a new view on re-designing non-volatile memory by the controllable/recoverable ferroelectric switching states and decreased consumption of energy with the help of mechanical confinement.

10-30-2017, HOUSTON, TX

Our study on the enhanced surface reaction kinetics by introducing anti-site defects appears online (doi:10.1038/s41467-017-01315-8). It has also been highlighted by Rice News, Futurity, United Press International, Science360 News, Eurekalert, PhysOrg, ScienceDaily, Nanowerk, and others.

09-25-2017, HOUSTON, TX

Finally!

An interesting study on two-dimensional Li diffusion behaviors and hybrid phase transformation kinetics in olivine lithium iron phosphate (LFP) electrode is accepted by Nature Communications. Here we combine operando hard X-ray spectroscopic imaging and phase-field modeling to elucidate the delithiation dynamics of single-crystal LFP microrods with long-axis along the [010] direction. This study not only presents the first direct proof of the previously predicted Surface-Reaction-Limited transformation behavior by Singh, Ceder and Bazant, but reveals a more subtle and complete picture of phase transformations in LFP and intercalation compounds in general. This is also my first paper on tuning interrelation between surface reaction kinetics and bulk diffusion behaviors by engineering defects and dislocations in phase-changing electrodes.

 

12-07-2016, HOUSTON, TX

Evan Hong was born in The Women’s Hospital of Texas at 12:12 pm on 12-07-2016. Welcome to this tiny but strong boy.

12-06-2016, HOUSTON, TX

Congratulations to Zibin for his great phd achievements. This is my first published paper of PMN-PT, whose thermodynamic analysis and phase-field simulations are based on my developed PMN-PT thermodynamic parameters several years ago. I am very excited for the successful applications of these thermodynamic analysis to a variety of interesting experimental observations on PMN-PT bulk or thin film configurations. More works will be published soon.