Fuel Cell Nano-Materials Group (Leader: Enrico TRAVERSA), International Center for Materials Nanoarchitectonics (Director: Masakazu AONO) has successfully developed two types of novel proton conducting oxide electrolytes for solid oxide fuel cells (SOFCs). By applying these electrolytes, the commercialization of SOFCs operating in the intermediate temperature range, 500 to 650¡ÆC, has come into sight.
SOFCs are environmental-friendly and efficient energy production devices. Reducing the operating temperature of SOFCs below 700¡ÆC is needed for a wide practical application of these devices. Yttrium-doped barium zirconate (BZY) is now considered as an alternative to the oxygen-ion conductor electrolytes conventionally used in SOFCs due to its higher bulk proton conductivity at low temperatures. BZY has not been exploited until now despite its excellent chemical stability because, when prepared as a ceramic polycrystalline material, it suffers from difficult sintering and proton conductivity is decreased by grain boundaries, which have a blocking effect.
Fuel Cell Nano-Materials Group has successfully developed two types of novel materials which satisfy all the three requirements for electrolyte: ion conductivity, chemical stability and sinterability, at high levels.
One is yttrium-doped barium zirconate with 10 mol% of praseodymium (BZPY). The addition of Pr improves the sinterability of BZY and dense samples are obtained after sintering at 1500¡ÆC for 8 hours. This material showed very high proton conductivity (above 0.01S/cm at 600¢ªC), comparable to the proton conductivity of BCZY, now proposed for proton conductor electrolyte, but with significantly better chemical stability, thereby resulting in realistic applicability in fuel cell devices.
The other material is indium-doped barium zirconate (BZI) on a NiO-BZY anode substrate. During sintering at 1450oC, a dense electrolyte film is formed and simultaneously indium evaporates, being substituted by yttrium. The final result is the achievement of a dense BZY electrolyte film on a NiO-BZY anode, which cannot be obtained at the same temperature with direct processing. The fuel cells using this electrolyte film showed the largest fuel cell performance, 0.169 W/cm2 at 600oC, ever reported for BZY-based electrolytes. The BZY film made by this method shows excellent chemical stability, indicating its potential for long-term operation.
These two materials are promising electrolyte materials for SOFC operating in the intermediate temperature range, 500 to 650¡ÆC, which allows reducing SOFC fabrication and operation costs, and thus accelerating their commercialization. The previous work of the group, published in Nature Materials on September 20th, introduced high-performance materials that show very high proton conductivity at even lower temperatures, but it was fabricated by using a special technology called pulsed laser deposition. In these new studies, high-performance electrolyte materials were obtained by simple co-pressing and subsequent sintering in the air, which is suitable for mass-production. This indicates the aforementioned results could accelerate the commercialization of SOFCs.
Mikiko Tanifuji | Research Asia Research News
Decoding cement's shape promises greener concrete
08.12.2016 | Rice University
Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D
08.12.2016 | DOE/Brookhaven National Laboratory
Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.
Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
09.12.2016 | Life Sciences
09.12.2016 | Ecology, The Environment and Conservation
09.12.2016 | Health and Medicine