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This study investigated the impact of NaAlO2 concentration in electrolytic solutions on micro-arc oxidation (MAO) coatings, focusing on their surface quality enhancement and corrosion resistance improvement. The surface morphology and microstructure of these coatings were assessed using scanning electron microscopy. Mechanical properties, such as hardness and wear resistance of MAO coatings, were tested. The hardness of the 6 g/L group was 411.2 HV. X-ray photoelectron spectroscopy examinations showed that MgAl2O4, CaMgP2O7, and MgSiO4 were the phases in the MAO coating. Antibacterial assessments were performed to evaluate the influence of NaAlO2 concentration, and the antibacterial rate of the 6 g/L group reached 97.08%. The hydrophilicity of the coatings was determined using water contact angle measurements, wherein the water contact angle of the 6 g/L was the lowest, at 58.25°. Corrosion resistance was evaluated with an electrochemical workstation. The findings revealed that the MAO coatings prepared with a NaAlO2 concentration of 6 g/L exhibited superior uniformity with fewer defects, enhanced corrosion resistance, and increased adhesive strength compared to other concentration groups. The 6 g/L NaAlO2 concentration MAO coating demonstrated the highest fitting coating resistance R3 (8.14 × 104 Ω∙cm2), signifying better corrosion resistance. [ABSTRACT FROM AUTHOR]

Mixing of two immiscible liquids consists of two sections that are liquid‐liquid dispersion and mass transfer intraphase or interphase. It plays a crucial role in the liquid‐liquid heterogeneous reactions. Here, the liquid‐liquid heterogeneous mixing efficiency in RPB reactor is experimentally assessed by a consecutive‐competitive chemical probe system. The diameters of dispersed phase droplets in RPB were measured and a correlation to predict the mean diameters were obtained. Based on the dispersed phase size and mass transfer characteristic, a model for predicting the segregation index of liquid‐liquid heterogeneous mixing in RPB was established with a deviation <20%. Based on this model, the characteristic time of liquid‐liquid heterogeneous mixing in RPB is determined to be in the range of 0.01–1 s. RPB exhibits a great process intensification potential for heterogeneous mixing process. [ABSTRACT FROM AUTHOR]

The ZK60 deformed magnesium alloy is treated by micro‐arc oxidation (MAO) and processed in the optimized silicate–phosphate electrolyte system, which is controlled under the two‐step current‐decreasing mode. The mechanism of discharge in the MAO process is investigated using the voltage–time curve and morphology of the spark discharge at different durations. The microstructures of the coatings fabricated at different durations are investigated. The rules of the coating ingrowth and/or outgrowth, the formation mechanisms of micropores, and microcracks in the coatings are explored systematically. The corrosion resistance of the coatings is measured by electrochemical methods. Through the exploration of the mechanism, two types of micropores in the coating are summarized: the in situ discharge growth type and the pores‐sealed type, and also three types of microcracks. The results illustrate the changes of the elements on the surface of the coating and Mg, O, and Si are incorporated into the coating formation process. The specimens show the best corrosion resistance after the two‐step current‐decreasing mode treatment. [ABSTRACT FROM AUTHOR]

Ni-rich layered cathode materials have large reversible capacity. However, they suffer from the cracking of the spherical particles, low Coulombic efficiency and fast capacity decay during cycling. Preparing a single-crystal Ni-rich cathode is a promising method to solve this problem due to its excellent structural stability. However, the morphology and electrochemical performance of single-crystal Ni-rich cathodes depend largely on the particle size and morphology of the hydroxide precursors. In this work, a suitable hydroxide precursor to synthesise single-crystal NCM622 with great dispersity and remarkable electrochemical performance is explored. Besides, the influence of grain size on the structural and thermal stability of the Ni-rich cathode material is further investigated. This work provides a reference to synthesize single-crystal Ni-rich cathodes with high electrochemical performance for lithium-ion batteries of the next generation. [ABSTRACT FROM AUTHOR]