Achieving long cycle life for all-solid-state rechargeable Li-I2 battery by a confined dissolution strategy

Rechargeable Li-I2 battery has attracted considerable attentions due to its high theoretical capacity, low cost and environment-friendliness. Dissolution of polyiodides are required to facilitate the electrochemical redox reaction of the I2 cathode, which would lead to a harmful shuttle effect. All-solid-state Li-I2 battery totally avoids the polyiodides shuttle in a liquid system. However, the insoluble discharge product at the conventional solid interface results in a sluggish electrochemical reaction and poor rechargeability. In this work, by adopting a well-designed hybrid electrolyte composed of a dispersion layer and a blocking layer, we successfully promote a new polyiodides chemistry and localize the polyiodides dissolution within a limited space near the cathode. Owing to this confined dissolution strategy, a rechargeable and highly reversible all-solid-state Li-I2 battery is demonstrated and shows a long-term life of over 9000 cycles at 1C with a capacity retention of 84.1%.

Hexagonal Boron Nitride Passivation Layer for Improving the Performance and Reliability of InGaN/GaN Light-Emitting Diodes

We introduce a low temperature process for coating InGaN/GaN light-emitting diodes (LEDs) with h-BN as a passivation layer. The effect of h-BN on device performance and reliability is investigated. At −5 V, the leakage current of the h-BN passivated LED was -1.15 x 10−9 A, which was one order lower than the reference LED’s leakage current of −1.09 × 10−8 A. The h-BN layer minimizes the leakage current characteristics and operating temperature by acting as a passivation and heat dispersion layer. With a reduced working temperature of 33 from 45 °C, the LED lifetime was extended 2.5 times following h-BN passivation. According to our findings, h-BN passivation significantly improves LED reliability.

Microstructure and Properties of Electroless Ni-P/Si3N4 Nanocomposite Coatings Deposited on the AW-7075 Aluminum Alloy

The article presents the results of mechanical and tribological tests of Ni-P/Si3N4 nanocomposite coatings deposited on the AW-7075 aluminum alloy using the chemical reduction method. The influence of the chemical composition on the Vickers microhardness determined by the DSI method was examined. The nanocomposite layers were made of Si3N4 silicon nitride in a polydisperse powder with a particle size ranging from 20 to 25 nm. The influence of the content of the dispersion layer material on the adhesion to the substrate was analyzed. The abrasive wear was tested and determined in the reciprocating motion using the “ball-on-flat” method. The surface topography was examined by the contact method with the use of a profilometer. Based on the obtained test results, it was found that the Ni-P/Si3N4 layers produced in the bath with the Si3N4 nanoparticle content in the amount of 2 g/dm3 are more resistant to wear and show greater adhesion than the Ni-P/Si3N4 layers deposited in the bath with 5 g/dm3 of the dispersion phase. NiP/Si3N4 layers provide protection against abrasive wear under various loads and environmental conditions.

SINGLE AND DOUBLE SHOT BLASTING TREATMENT OF 304 STAINLESS STEEL

Properties enhancement through surface modification has been established as a method to improve the dispersion quality of case hardening treatment. Improvement of dispersion thickness layers resulted in properties enhancement of metallic material. This study investigates the effect of shot blasting parameters which are single (SB) and double (DB) sand blasting on boronizing dispersion layer of 304 stainless steel. Boronizing treatment is conducted using paste boron at temperature of 900˚C for 6 hours holding time. The dispersion layer measurement and phase identification were evaluated through optical microscope and XRD analysis. Vickers hardness test and surface roughness analysis were also conducted .The result shows that noticeable enhancement of dispersion layer thickness was observed after conducting double sand blasting as compared to single sand blasting. Thicker dispersion layer leads to the increment of hardness value and also enhancement in surface roughness properties.

Boron Dispersion Layer of Paste Boronized 304 Stainless Steel before and after Shot Blasting Process

Boronizing had been extensively used in enhancing the properties of metallic material such as steel by formation of hard casing on the surface of the substrate. This study highlighted the effect of applying surface deformation process which is shot blasting on the dispersion layer of paste boronized 304 stainless steel. Boronizing treatment was conducted using two different temperatures which are 850°C and 950°C for 6 hour holding time. Shot blasting process was conducted onto the surface of the samples before boronizing process in order to allow deeper boron dispersion layer. Microstructure and boron dispersion layer measurement were then accomplished using optical microscope. XRD analysis was performed to validate the existence of Fe2B phases and Rockwell hardness test was also conducted to obtain the hardness values. The results indicated that combinations of high boronizing temperature and shot blasting process facilitate deeper dispersion layer. Deeper dispersion layer are paramount as it will enhanced the hardness and wear properties.

Mass Exchange Dynamics During the Second Filtration Drying Period

The work is dedicated to theoretical and experimental investigations of kinetics and dynamics of filtration drying of capillary and pore materials, and mineral granulated fertilizers, in particular. The proposed physical model of a moist particle and the differential system of equations which describes heat exchange in the second drying period enables to determine the transfer velocity of mass-exchange zone in a dispersion layer of the material during filtration drying.