Route to High-Performance Micro-solid Oxide Fuel Cells on Metallic Substrates

Abstract

Micro-solid oxide fuel cells based on thin films have strong potential for use in portable power devices. However, devices based on silicon substrate typically involves thin-film metallic electrodes which are unstable at high temperatures. Devices based on bulk metal substrates 2 overcome these limitations, though performance is hindered by the challenge of growing state-ofthe-art epitaxial materials on metals. Here, we demonstrate for the first time the growth of epitaxial cathode materials on metal substrates (stainless steel), commercially supplied with epitaxial electrolyte layers (1.5 m (Y 2 O 3 ) 0.15 (ZrO 2 ) 0.85 (YSZ) + 50 nm CeO 2 ). We create epitaxial mesoporous cathodes of (La 0.60 Sr 0.40 ) 0.95 Co 0.20 Fe 0.80 O 3 (LSCF) on the substrate by growing LSCF /MgO vertically aligned nanocomposite (VAN) films by pulsed laser deposition (PLD), followed by selectively etching out the MgO. To enable valid comparison with literature, the cathodes are also grown on single-crystal substrates, confirming state-of-the-art performance with an area specific resistance of 100 Ω at 500° C and activation energy down to 0.97 eV. The work marks an important step towards the commercialisation of high-performance microsolid oxide fuel cells for portable power applications.1.

Tailored nano-columnar La2NiO4 cathodes for improved electrode performance

“…On the other hand, apparent activity can be tuned by extending the active electrode area due to enhanced ionic conductivity (mainly in μm thick porous electrodes), or via increasing the specific surface area (SSA, e.g. total topographic surface area/in-plane area) by forming three-dimensional, nano-architectured morphologies in thin film electrodes, such as nanofibrous, 25,26 mesoporous 27,28 and columnar structures. 29 However, a distinct separation between intrinsic and apparent activity is not always possible, as in nano-engineered (composite) materials these two effects are strongly coupled.…”

High ionic conductivity in fluorite δ-bismuth oxide-based vertically aligned nanocomposite thin films

“…comprised of an epitaxial substrate anode (e.g. Ni-YSZ) on either Si 35 or metal 36 with two VAN layers above the anode layer, rst a d-Bi 2 O 3 -based VAN electrolyte and followed by a d-Bi 2 O 3 based VAN cathode. Such double VAN ionic structures are readily possible.…”

Fuel Cells - An Overview of Their Green Value and Readiness Levels

“…To abate these challenges, SOFC research is focused on developing materials that meet the required temperature and mechanical constraints (54) as well as developing intermediate SOFCs (IT-SOFC) that operate around 600 °C -800 °C and low temperature SOFCs (LT-SOFCs) that operate around 300 °C -600 °C (134,135). Though lower temperature SOFCs are attributed with lower ionic conductivity and inadequate electrolytic activity (134,136,137), advances include the development of nanoscale membranes (137,138) and the development of electrolyte layer-free fuel cells (EFFCs).…”