Electrophoretic Codeposition of La_0.6Sr_0.4Co_0.8Fe_0.2O_3−δ and Carbon Nanotubes for Developing Composite Cathodes for Intermediate Temperature Solid Oxide Fuel Cells

Abstract

Carbon nanotubes (CNTs)/La0.6Sr0.4Co0.8Fe0.2O3−δ (LSCF) composite films have been fabricated by electrophoretic codeposition on Ce0.9Gd0.1O1.95 (CGO) substrates. CNTs are used as a sacrificial phase to produce ordered porous LSCF cathodes for intermediate temperature solid oxide fuel cells. The synthesis of LSCF powder by a modified sol–gel route is presented. The possible mechanism of formation of CNT/LSCF composite nanoparticles in suspension is discussed. Moreover the optimal suspension composition and the conditions for achieving successful electrophoretic deposition (EPD) of CNTs/LSCF composite nanoparticles were evaluated. Experimental results showed that the CNTs were homogeneously distributed and mixed with LSCF nanoparticles forming a mesh‐like structure, which resulted in a highly porous LSCF film when the CNTs were burned out during heat treatment in air at 800°C for 2 h. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray diffraction (XRD) techniques were employed to characterize the microstructure of the precursors and of the composite films.

Electrophoretic deposition of nanostructured-TiO2/chitosan composite coatings on stainless steel

“…Titania (TiO 2 ) is a biocompatible ceramic material being used to develop biomedical coatings sometimes also in combination with hydroxyapatite. [1][2][3][4][5][6][7] Titania has a proven biocompatibility 5,[8][9][10] and it can enhance the implant integration with host tissue when used in bone tissue replacement applications. [11][12][13][14] Titania also presents antibacterial properties, which increases its possible benefits in the biomedical field.…”

“…[15][16][17] Numerous techniques are employed to produce TiO 2 coatings on metallic surfaces, such as plasma spray technique, 18,19 micro-arc oxidation (MAO), 4 sol-gel 20 or electrophoretic deposition (EPD). 1,3,21,22 EPD emerges as a versatile, simple and low cost technique to create highly homogeneous coatings with some advantages, like the possibility to deposit materials on 3D structures as well as on porous materials, e.g. scaffolds.…”

“…EPD of TiO 2 has been carried out using different solvents, mainly acetylacetone and acetone, [28][29][30][31] but water and water-ethanol mixtures have also been used in a reduced scale. 3,[32][33][34][35] Ceramic deposits obtained by EPD require a sintering process at high temperature to achieve high density materials. To avoid this sintering step, which can lead to possible degradation and microstructural damage of the coating, e.g.…”

Opportunities, Challenges and Prospects for Electrodeposition of Thin-Film Functional Layers in Solid Oxide Fuel Cell Technology

“…The most complete review of the EPD of cathode materials, including that in micro-tubular cells, is presented in our recent review [22]. In the work of the Boccaccini group on the electrophoretic co-deposition of the cathode material LSCF and carbon nanotubes (CNT) on a supporting solid electrolyte [76], for instance, the conductivity of the GDC substrate, was provided by the deposition of an Ag sublayer. EPD was carried out from a composite CNT/LSCF suspension (in a wt.…”

“…A symmetrical cell with LSFC-SDCC films deposited on the SDCC electrolyte and sintered at 600 • C showed a polarization resistance of 0.68 Ω cm 2 at 650 • C. It should be noted that the direct formation of a porous deposit of a cathode material by the EPD method on a non-conducting gas-tight solid electrolyte surface is impossible due to the absence of electronic conductivity on the electrolyte surface. This problem was solved by creating a conductive sublayer, for example, graphite [74], a conductive polymer-polypyrrole [75]-by means of surface metallization with Ag or Au [73,76], or by deposition of a Pt layer on the opposite side of the supporting electrolyte, which, after deposition, served as an anode during the cell operation [77]. The most complete review of the EPD of cathode materials, including that in micro-tubular cells, is presented in our recent review [22].…”