Nanostructured Ni-YSZ by Atomic Layer Deposition

Abstract

Nickel yttria-stabilized zirconia (Ni-YSZ) is used as anode material for solid oxide fuel cells (SOFCs). The electrochemical performance of Ni-YSZ anodes can be improved when the size of constituent particles of nickel is reduced. However, at SOFC high temperature operating environments, nano-sized Ni particles suffer from sintering. Nanoscale Ni-YSZ anodes can undergo severe structure changes. In this work, a unique approach of fabricating a nanostructured Ni-YSZ anode is demonstrated by combining atomic layer deposition (ALD) and glancing angle deposition (GLAD) techniques whereby nickel nanoparticle sintering is prevented at high temperatures with as thin as 1.9 nm YSZ ALD coating on the nickel; the surface area of the resulting Ni-YSZ anode was found to increase more than 3 times that of a planar electrode. In addition, the novel ALD/GLAD coating approach used here provides an ionic conductive YSZ electrolyte phase combined with an electrical conductive Ni phase whereby porosity can be controlled through deposition and post-deposition annealing. In addition, the surface roughness of Ni-YSZ anode decreases with increasing YSZ coating layer thickness and it is unaffected by the post-deposition annealing process. Conductivity measurements of the Ni-YSZ anodes at room temperature show a resistivity in the order of 10−4 cm·S−1.

A review on the preparation of anode materials and anode films for solid oxide fuel cell applications

“…The study also suggested that the improvement is doable with other catalytic metals such as Ni, Cu, and Co. Meanwhile, ALD has been used with the glancing angle deposition (GLAD) technique to prevent the sintering of the Ni at high temperature 69 . ALD was used to deposit a nanoscale YSZ layer uniformly and to stabilize the Ni particles.…”

“…Meanwhile, ALD has been used with the glancing angle deposition (GLAD) technique to prevent the sintering of the Ni at high temperature. 69 ALD was used to deposit a nanoscale YSZ layer uniformly and to stabilize the Ni particles. Besides, it can provide an ionic conductive phase.…”

“…27 Some of the approaches that are used to synthesize anode materials including ball milling, [28][29][30][31][32] solid-state reaction (SSR) method, [33][34][35] template-based synthesis method, [36][37][38] and wet chemical methods (WCMs), such as sol-gel, 15,[39][40][41][42][43][44][45] co-precipitation, [46][47][48][49] hydrothermal and solvothermal methods, 48,50,51 and combustion method. [52][53][54][55][56][57][58] Various deposition methods were also discussed and categorized in several groups including physical deposition, [59][60][61][62][63][64][65][66] chemical deposition, [67][68][69] and colloidal deposition. 32,[70][71]…”

“…Some of the approaches that are used to synthesize anode materials including ball milling, 28‐32 solid‐state reaction (SSR) method, 33‐35 template‐based synthesis method, 36‐38 and wet chemical methods (WCMs), such as sol‐gel, 15,39‐45 co‐precipitation, 46‐49 hydrothermal and solvothermal methods, 48,50,51 and combustion method 52‐58 . Various deposition methods were also discussed and categorized in several groups including physical deposition, 59‐66 chemical deposition, 67‐69 and colloidal deposition 32,70‐76 . Other alternative fabrication techniques such as dry‐pressing, tape calendaring, impregnation/infiltration, and 3D‐printing were also explored in this review 77‐86 .…”

Recent Advances in Materials Design Using Atomic Layer Deposition for Energy Applications

“…[ 215 ] However, the electrochemical performance cathode drops at low operating temperature due to poor oxygen reduction reaction (ORR). Surface modification of thermally stable metal oxides such as doped ZrO 2 , [ 216 ] CeO x , [ 217 ] Al 2 O 3 , [ 218 ] TiO x , [ 219 ] and SnO x , [ 220 ] perovskite‐based cathodes materials ((Mn 0.8 Co 0.2 ) 3 O 4 , [ 221 ] Pr 6 O 11 [ 222 ] ), and metals (pure and alloys) (Pt, [ 223 ] Ru, [ 224 ] Pd, [ 225 ] Ni, [ 226 ] Al, [ 227 ] PtRu, [ 228 ] NiPd, [ 225 ] NiRu [ 229 ] ) have been engineered via the ALD technique. These nanostructured coatings/electrode materials are proven to be effective in stabilizing the catalyst surface without sacrificing the surface activity.…”