Relaxation of Stress Propagation in Alloying-Type Sn Anodes for K-Ion Batteries.

Alloying-type metallic tin is perceived as a potential anode material for K-ion batteries owing to its high theoretical capacity and reasonable working potential. However, pure Sn still face intractable issues of inferior K+ storage capability owing to the mechanical degradation of electrode against large volume changes and formation of intermediary insulating phases K4 Sn9 and KSn during alloying reaction. Herein, the TiC/C-carbon nanotubes (CNTs) is prepared as an effective buffer matrix and composited with Sn particles (Sn-TiC/C-CNTs) through the high-energy ball-milling method. Owing to the conductive and rigid properties, the TiC/C-CNTs matrix enhances the electrical conductivity as well as mechanical integrity of Sn in the composite material and thus ultimately contributes to performance supremacy in terms of electrochemical K+ storage properties. During potassiation process, the TiC/C-CNTs matrix not only dissipates the internal stress toward random radial orientations within the Sn particle but also provides electrical pathways for the intermediate insulating phases; this tends to reduce microcracking and prevent considerable electrode degradation.

Effects of Coupled-/soluble-Copper, Generating from Copper-doped Titanium Dioxide Nanotubes on Cell Response.

BACKGROUND: Endothelialization in vitro is a very common method for surface modification of cardiovascular materials. However, mature endothelial cells are not suitable because of the difficulty in obtaining and immunogenicity. METHODS: In this patent work, we determined the appropriate amount of copper by constructing a copper- loaded titanium dioxide nanotube array that can catalyze the release of nitric oxide, compared the effects of coupled-/soluble-copper on stem cells, and then induced stem cells to differentiate into endothelial cells. RESULTS: The results showed that it had a strong promotion effect on the differentiation of stem cells into endothelial cells, which might be used for endothelialization in vitro. CONCLUSION: SEM and EDS results prove that a high content of copper ions are indeed doped onto the surface of nanotubes with small amounts of Cu release. The release of NO confirms that the release of several samples within a period of time is within the physiological concentration.