New Publication in “Chemistry Select”

Developing TiO2 crystals with specific morphologies and nanostructured architectures is highly desirable in energy storage, conversion and catalysis applications. Herein, we report a close correlation between mechanical strength of the TiO2 precursors and their different crystallization pathways. …

New Publication in “Nature Communications”

Any dielectric material under a strain gradient presents flexoelectricity. Here, we synthesized 0.75 sodium bismuth titanate −0.25 strontium titanate (NBT-25ST) core–shell nanoparticles and observed domain-like nanoregions (DLNRs) up to an extreme temperature of 800 °C. …

New Publication in “Acta Materialia”

The focus of this study is the distribution of surface-induced bulk stresses in a LiCoO2 nanoparticle and their impact on the migration of Li-vacancies. At these length scales, surface effects gain an appreciable impact not only on the electrochemical and mechanical behavior of the electrode material, but also on defect thermodynamics. …

New Publication in “Physical Review Applied”

In this work we study the impact of internal bias fields on the electrocaloric effect (ECE), utilizing an analytical model and ab-initio-based molecular dynamics simulations. We reveal the complex dependency of the ECE on field protocol and relative strength of internal and external fields. …

New Publication in “Energy Technology”

We discuss and analyze the occurrence of the inverse (or negative) electrocaloric effect, where the isothermal application of an electric field leads to an increase in entropy and the removal of the field decreases the entropy of the system under consideration. We show that in all these cases the inverse electrocaloric effect is related to the presence of competing phases or states which are close in energy and can easily be transformed with the applied field. …

New Publication in “Energy Technology”

the highest electrocaloric effect is observed in poled hard PZT with the field applied along the poling direction, which is related to the reduced hysteresis losses caused by internal electric fields associated with defect complexes. The weak hysteretic dependency of polarization as function of the electric field in hard PZT also allows inducing an inverse electrocaloric effect. …

New Publication in “Materials Horizons”

The insertion of Li-ions within cathode materials during the discharging of a battery oftentimes brings about one or more structural transformations. Here we demonstrate compositional striping modulations between Li-rich and Li-poor domains along the edges of individual nanowires of Li-ion-intercalated V2O5 based on analysis of hyperspectral X-ray microscopy data. …

New Publication in “Acta Materialia”

In this study, we found that for a Nd-Cu diffusion parallel to the texture axis the increase in Hc is higher than for a diffusion perpendicular to it and strongly depends on the diffusion depth whereas remanence develops in an inverse manner. …

Prof. Xu gave a tutorial entitled “Multi-physics Multi-scale Modeling of Li-ion Batteries” in the Energy Research Workshop of APS March Meeting 2018, 4 Match.

New Publication in “Materials”

In the present study, the effect of the chemical and phase composition on the thermal properties of silicon oxide carbides (SiOC) has been investigated. Dense monolithic SiOC materials with various carbon contents were prepared and characterized with respect to their thermal expansion, as well as thermal conductivity. …