Atomic layer deposition of GDC cathodic functional thin films for oxide ion incorporation enhancement

Abstract

In this paper, we report successful fabrication of a gadolinia-doped ceria (GDC) thin film using atomic layer deposition (ALD) for improving the performance of solid oxide fuel cells (SOFCs). By varying the deposition conditions and adjusting the configuration of the ALD supercycle, the doping ratio of ALD GDC was controlled. The morphology, crystallinity, and chemical composition of ALD GDC thin films were analyzed. ALD GDC showed different surface chemistry, including oxidation states, at different doping ratios. The application of ALD GDC in a SOFC led to an output power density enhancement greater than 2.5 times. With an anodic aluminum oxide (AAO) porous support structure, an ALD GDC thin film SOFC (TF-SOFC) showed a high power density of 288.24 mW/cm 2 at an operating temperature of 450°C. K E Y W O R D S atomic layer deposition, functional interlayer, Gadolinia-doped ceria, low-temperature solid oxide fuel cells, oxide ion incorporation T A B L E 1 Summary of atomic layer deposition (ALD) gadolinia-doped ceria (GDC) parameters: supercycle configuration, deposition rate per supercycle, and deposition cycles Recipe Supercycle configuration Deposition rate (Å/supercycle) Number of cycles Actual thickness (nm) GDC 2:1

Nanocrystal Engineering of Thin-Film Yttria-Stabilized Zirconia Electrolytes for Low-Temperature Solid-Oxide Fuel Cells

“…Therefore, even further performance enhancement is expected if electrode modifications are applied. It is also noteworthy that only a limited number of reported AAO-supported SOFCs have achieved higher performance than the one reported in this study, and they all have been achieved through utilizing more complex electrode materials or employing additional chemical vapor deposition processes. ,− Specifically for all-sputtered TF-SOFCs, Yu et al reported 477 mW/cm 2 at 500 °C with a nanostructure-tailored Ni anode (Ni/GDC/YSZ/GDC/Pt cell configuration). Ren et al reported 480 mW/cm 2 at 500 °C with a Ni–YSZ/YSZ/GDC/LSC-GDC cell by adjusting the cosputtering conditions for the LSC-GDC cathode.…”

Nanoscale interface engineering for solid oxide fuel cells using atomic layer deposition

“…5e ). 39 The optimal performance was achieved when 18.8 mol% of Gd-doped ceria was inserted as an inter-layer, and power density of 288.24 mW cm −2 was obtained with three times greater performance at 450 °C ( Fig. 5f ).…”

“…In the same manner, studies aiming to enhance SOFC performance outcomes by improving the electrode-electrolyte interface property by inserting a very thin inter-layer with various compositions between the electrode and electrolyte are ongoing. [38][39][40] Recently, Kim et al deposited various compositions of gadolinia-doped ceria (GDC, Gd 2 O 3 doping ratio: 11.9 mol%, 13.9 mol%, 18.8 mol%, and 25.2 mol%) onto the interface of YSZ and a Pt electrode and measured the peak power density (Fig. 5e).…”

“…Precious metals or transition metals such as Pt, Ag, Ni, and Ru are often used as SOFC electrode materials due to their high conductivity as well as their superior catalytic activity towards the ORR on the cathode side and the fuel oxidation reaction on the anode side. [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] However, due to their high operation temperatures, electrode materials can become agglomerated, resulting in an interruption of the electron flow and decreases in the electrode surface area and triple-phase boundary (TPB), known as the major reaction sites. 44 These phenomena cause irreversible performance degradation.…”

A Comprehensive Review of Thermal Management in Solid Oxide Fuel Cells: Focus on Burners, Heat Exchangers, and Strategies

“…One solution focuses on utilizing highly active component materials, starting with electrode materials of higher catalytic activity or electrolytes of higher ionic conductivity. However, the selection of SOFC component materials that reduce temperature while remaining cost-effective is quite limited [169,170]. Alternatively, temperature reduction can be achieved through improvements in manufacturing processes, such as nanostructured components and thin-film electrolytes [171,172].…”