Near zero-strain silicon oxycarbide interphases for stable Li-ion batteries.

We investigate silicon oxycarbide nanotubes that incorporate Si, SiC, and silicon oxycarbide phases, which exhibit near zero-strain volume expansion, leading to reduced electrolyte decomposition. The composite effectively accommodates the formation of c-Li15Si4, as validated by in situ TEM analyses and electrochemical tests, thereby proposing a promising solution for Li-ion battery anodes.

Precise control of heat-treatment conditions to improve the catalytic performance of V2O5/TiO2 for H2S removal.

The purpose of this study is to investigate the influences of atmospheric gas and temperature while preparing V2O5/TiO2 catalysts to find a suitable heat-treatment method to improve catalytic performance during the process of H2S removal. The catalysts prepared by wet-impregnation were heat-treated at different temperatures (400 or 600 â„ƒ) under various atmospheres (Air, N2, or H2). The catalytic tests demonstrated that the catalyst heat-treated at 400 â„ƒ under N2 atmosphere (N-400) possessed excellent catalytic activities regarding H2S conversion (96.4%) and sulfur yield (89.1%). The characterization results revealed that the mild reducing condition employed for N-400 led to the formation of partially reduced V2O5 crystals and a strong V-Ti interaction owing to the anatase TiO2 phase, resulting in the high oxygen vacancies on the catalyst surface. However, severe reducing conditions (H2 or N2 with 600 â„ƒ) or the higher temperature (600 â„ƒ) induced highly reduced V2O5-x or rutile TiO2 related to a weak V-Ti interaction, respectively, which facilitated lower oxygen vacancies. This study is the first to demonstrate the significance of a precisely controlled heat-treatment to enhance catalytic performance for H2S removal.

Grain Growth Behavior of 0.95(Na0.5Bi0.5)TiO3-0.05BaTiO3 Controlled by Grain Shape and Second Phase.

The grain growth behavior of 0.95(Na0.5Bi0.5)TiO3-0.05BaTiO3 (mole fraction, NBT-5BTdid not appear in any of the NBT-5BT samples with excess Bi2O3. The amount of liquid phase increased as the amount of Bi2O3 increased. Therefore, the rate of grain growth could be decreased by the increasing the distance for the diffusion of atoms. These observations allowed us to conclude that the growth of Bi2O3-excess NBT-5BT grains is governed by the growth of facet planes via the two-dimensional nucleation grain growth mechanism during changing grain shape and amount of liquid.