Dual layer electrode coating for alkaline water electrolysis was prepared by plasma spraying. For improving performance this work aims at reducing the oxide in electrode coating. Regarding the necessity of obtaining high specific area, atmospheric plasma spray was employed under protection of argon which was used as shrouding gas. Composite cathode was established on Ni-coated perforated steel sheet with crushed and gas atomized Nickel-based alloy powders. The dual-layer structure was a composite of 5 layers of NiAl at the bottom and 10 layers of NiAlMo as the top layer. Microstructure and morphology were studied by scanning electron microscope (SEM). Element content was estimated by energy dispersive spectrometer (EDS). Enthalpy probe was introduced for measuring plasma temperature and velocity as well as gas composition. Numerical calculation was carried out with same condition for better understanding the shrouding effect. The results showed moderate protection by using of arranged gas shrouding. Overall, in the dual layer region, oxygen content was decreased by 0.3%, from 3.46% to 3.15%. With gas shrouding coating exhibited similar element contents as coating sprayed by VPS. However, no obvious difference was observed in microstructure and morphology with or without gas shrouding.

Porous copper coatings, which act as wicks for liquid transport, were fabricated using a flame spraying process. Copper and aluminum powders were fed independently into the spray torch and deposited on copper substrates to form a composite coating. The aluminum was subsequently removed using chemical leaching leaving a porous copper coating behind. Varying the feed rate of aluminum powder allowed the coating porosity to be controlled. Channels to enhance liquid flow were made in some of the porous copper coatings by placing pieces of aluminum wire mesh on the copper substrate before spraying. During spraying the sprayed powders passed through the mesh opening and created pyramid shaped arrays on the substrates. The groove width was controlled by using different wire mesh sizes. Coatings were made with porosity varying from 2 to 44 %, and groove width ranging from 0.16 to 0.53 mm. The capillary performance of the coatings was evaluated experimentally by measuring the rate of rise of ethanol in the coatings. The rate of rise increased with coating porosity, and decreased with groove width.

Solid oxide fuel cell (SOFC) has been developed for a hundred year and met a great challenge on material design and marketing. In recent years, new SOFC materials are dug up to achieve high energy-output performance at lower working temperature (300~600 °C), namely low-temperature SOFC (LTSOFC). In this study, Ni-Co-Al-Li oxide (NCAL) was used for making dense, thin and uniform coatings on grooved bipolar electrode substrate for LTSOFC. Low-pressure plasma spray (LPPS) technology was applied to manufacture the NCAL coatings. The performance of a fuel cell package using the coated bipolars was tested between 350 and 600 °C, showing 6~8 W power output with 4 single fuel cells (active area of 25 cm 2 ). The LPPS technology is believed to be one of the ultimate ways for manufacturing the thin film/coatings for SOFC applications in future.

This study demonstrates a low-pressure coating (LPC) technique for the deposition of titania films. In this process, compressed air is used to accelerate angular titania feedstock into a substrate such as stainless steel, producing a photoactive surface consisting of embedded titania particles. The method is relatively inexpensive, requiring only the basic materials and an air supply. A range of LPC titania coatings were produced, varying nozzle stand-off distance, air pressure, and substrate exposure time. Samples are characterized via SEM and EDX analysis, photocurrent measurements, and NOX removal testing.

In this work, a dense YSZ coating with homogenous structure was produced by atmospheric plasma spraying (APS) on a NiO-YSZ anode supported by a porous metal substrate. A powder separator was used to limit fluctuations in the particle stream, thus stabilizing the process. During feeding, the YSZ powder was separated into fine particles that were fed directly to the plasma and coarse particles that were collected and reused. The coatings obtained exhibited high homogeneity both across the surface and through the thickness. SEM images showed that the YSZ layer was crack-free and that its porosity ratio rivaled that of vacuum plasma sprayed zirconia when two separators were used. Based on these observations and the results of gas leak rate measurements, the potential of online powder separation to improve SOFC electrolyte performance has been established.

Lanthanum gallate doped with strontium and magnesium (LSGM) is a good electrolyte candidate for Intermediate-temperature solid oxide fuel cells (IT-SOFCs). In this study, low-temperature sintering is used to increase the density of LSGM coatings prepared by vacuum cold spraying (VCS). LSGM layers with different thickness were deposited by VCS on NiO-YSZ substrates. In order to suppress chemical reactions between Ni and LSGM, the substrates were coated with gadolinium-doped ceria by tape casting. After sintering at 1200 °C, the coatings were found to be denser in most regions due to grain growth, which appears to be accompanied by cracking, particularly in thicker layers. A second layer was deposited on the annealed coatings to seal the cracks and the two-layer structure was further sintered. Gas permeability test results show that the multilayer films are dense enough to consider their use as electrolyte membranes in IT-SOFCs.

In this study, a 30 kW RF plasma reactor is used to synthesize metallic (Ni) and intermetallic (Mg 2 Ni) nanoparticles along with carbon-encapsulated Ni. The system was configured with injection probes at the top and bottom of the torch to facilitate the synthesis of compounds as well as core-shell particle structures. Materials used as precursors include methane, Ni, Mg, and pre-alloyed Mg 2 Ni powder. By feeding Ni together with methane, nickel nanoparticles encapsulated with 6-10 layers of graphite were produced. The core-shell particles and other samples collected were analyzed using X-ray diffraction and electron imaging techniques and were found to be spherical in shape and less than 100 nm in diameter.