In situ formation of an intimate solid-solid interface by reaction between MgH_(2) and Ti to stabilize metal hydride anode with high active material content

MgH_(2) and TiH_(2) have been extensively studied as potential anode materials due to their high theoretical specific capacities of 2036 and 1024 mAh/g,respectively.However,the large volume changes that these compounds undergo during cycling affects their performance and limits practical applications.The present work demonstrates a novel approach to limiting the volume changes of active materials.This effect is based on mechanical support from an intimate interface generated in situ via the reaction between MgH_(2) and Ti within the electrode prior to lithiation to form Mg and TiH_(2).The resulting Mg can be transformed back to MgH_(2) by reaction with LiH during delithiation.In addition,the TiH_(2) improves the reaction kinetics of MgH_(2) and enhances electrochemical performance.The intimate interface produced in this manner is found to improve the electrochemical properties of a MgH_(2)-Ti-LiH electrode.An exceptional reversible capacity of 800 mAh/g is observed even after 200 cycles with a high current density of 1 mA/cm^(2) and a high proportion of active material(90 wt.%)at an operation temperature of 120℃.This study therefore showcases a new means of improving the performance of electrodes by limiting the volume changes of active materials.

A Study on Solid/Melt Interfaces and the Formation of<100> Texture in Solidified FCC Metals

The (100) texture of solidified fcc metals, caused by the preferential (100) dendrite growth, could be closeIy related to solid/melt interfaces which behave differently along different crystallographic orientation. The stability and roughness of {111} and {100} solid/melt interfaces of fcc metals were investigated using a modified Temkin multi-layer model. It is demonstrated that {100}crystal/melt interface is more unstable and rougher than {111} interface. The effect of the stability of crystal/melt interface on the (100) texture formation in solidified fcc metals has been analysed and discussed.

Nitrogen and fluorine co-doped graphene for ultra-stable lithium metal anodes

The heteroatom doping strategies have been utilized to effectively improve the performance of the carbon-based hosts,such as graphene,for lithium(Li)metal in high energy density lithium metal batteries.However,solely doped graphene hosts often need the assistance of other materials with either better lithiophilicity or electronic conductance to achieve smooth and efficient deposition of Li,which adds extra weight or volume.Herein,graphene co-doped by nitrogen and fluorine(NFG)is employed as a stable host for Li,where the N-doping provides lithiophilicity and electronic conductivity lacked by F-doping and the F-doping facilitates fast formation of solid electrolyte interphase(SEI)retarded by N-doping.The well regulation of Li plating/stripping and SEI formation is verified by quickly stabilized and small-magnitude voltage hysteresis,which stands out in Li hosts based on doped graphene and leads to excellent long-term cycling performance of NFG based electrodes.A voltage hysteresis of 20 mV is observed for more than 850 h in the symmetrical cell.The remarkable efficiency of lithium usage is confirmed by the highcapacity retention of a full cell paired with LiFePO_(4)(LFP),which exceeds 70%after 500 cycles.This work presents an innovative perspective on the control of Li plating/stripping by simultaneously introducing two kinds of dopants into graphene and paving the way for exploring practical Li metal batteries.

An update on electrostatic powder coating for pharmaceuticals

Derived from dry powder coating of metals, electrostatic powder coating for pharmaceuticals is a technology for coating drug solid dosage forms. In this technology, coating powders, containing coating polymers, pigments, and other excipients, are directly sprayed onto the surface of the solid dosage forms through an electrostatic gun without using any organic solvent or water. The deposited coating powders are further cured to form a coating film. Electrostatic powder coating technology has many advantages compared to other pharmaceutical coating methods. It can eliminate the limitations caused by the organic solvent in solvent coating such as environmental issues and health problems. And electrostatic powder coating technology also surpasses aqueous coating due to its shorter processing time and less energy consumption, leading to a lower overall cost. Furthermore, the utilization of electrical attraction can promote the movement of coating powders towards the substrate, leading to an enhanced coating powder adhesion and coating efficiency, which make it more promising compared to other dry coating technologies. The objective of this review is to summarize the coating principles, apparatus, and formulations of different electrostatic powder coating technologies, giving their advantages and limitations and also analyzing the future application in the industry for each technology