FuelCellsWorks

Show a Denko KK of Japan has developed a catalyst for polymer electrolyte fuel cells (PEFC) to replace expensive platinum (Pt)-based catalysts. The new catalyst adds carbon (C), nitrogen (N) and other elements to niobium (Nb) and titanium (Ti) oxides (Fig 1). The development was advanced as part of the “non-precious metal oxide-based cathode for PEFCs” project of the New Energy & Industrial Technology Development Organization (NEDO) of Japan, by a group headed by Professor Ken-Ichiro Ota of Yokohama National University of Japan.

In PEFCs, catalysts promote the chemical reaction between hydrogen (H) and oxygen (O). Pt, currently used as the catalyst, is a rare metal that costs over Yen4,000 per gram, and the high cost of catalysts has been a major obstacle to widespread adoption of PEFCs.

Another problem is that Pt dissolves in the air electrode, which is in an oxidizing environment. The development of a substitute has been a major priority from the viewpoint of durability as well. Nb- and Ti-based oxides face few restrictions in terms of resources, and because they are oxides they are less susceptible to being dissolved than Pt. Material cost, says a source at Showa Denko, is “… no more than 5% of the platinum catalyst.”

Catalytic Strength Index

The newly developed Nb- and Ti-based oxide catalysts have oxidation/reduction potential (ORP, an index of catalytic strength) of 1V or better, about the same as Pt, suggesting high performance as catalysts (Fig 2). When it comes to performance in fuel cells, however, “Platinum performance is still four or five times higher,” says a source at Showa Denko. The firm joined the NEDO project in July 2008, and says there is still considerable room for improvement. For example, the catalyst particles are large at about 40nm, but they expect performance to rise with smaller particle sizes.

According to Showa Denko, cell evaluation for fuel cell applications indicated an open voltage of 1V or higher, and a durability of at least 500 hours. Performance verification testing is still under way, with new records being set that make it the most effective Pt-substitute catalyst in the world at present. The remaining issue is establishing a volume production method. “We still can’t assure stable performance in 4-gram batches,” reveals an engineer at the firm.

Photo:AIST (Advanced Industrial Science And Technology)

SOFC module prototypes using micro-tube SOFC cells were successfully developed. Those SOFC modules operate at 650 degrees of centigrade or lower. A number of miro-tube SOFC cells were integrated into an SOFC unit (Fig. 2). Two SOFC units were combined to form an SOFC module. A total number of micro-tube SOFC cells used for the SOFC module was 90. The output power of the SOFC module was 50 watts or higher. The power generation efficiency was 40% or higher. The power generation density was 2 W/cm3.
Another SOFC module of 200 W output power was also manufactured using eight SOFC units (Fig. 3). The SOFC module, which consists of eight SOFC units, is considerably complex in structure. In this study, the gas manifolds and the current collecting electrodes were further assembled into such a complex integration structure.
Thus, the micro-tube SOFC cell high-density packaging technique for SOFC modules and its evaluation technique were successfully established.
The co-developer has a plan to apply the SOFC module of 200 W output power to APUs (auxiliary power units), small cogeneration systems, etc., and to evaluate the resultants. The results of this study will be presented in The Eleventh International Symposium on Solid Oxide Fuel Cells (SOFC-XI)、in Vienna, Austria from October 4-9, 2009

Co-developed by:
AIST (Advanced Industrial Science And Technology)
FCRA (fine ceramics research association)
NGK Spark Plug Co., Ltd
TOHO Gas Co., Ltd.

SOFC is usually used for the large-scale power plant since its operation temperature is high (800-1000 degrees of centigrade). The SOFC has many advantages, for example, of high power generation efficiency, simple structure, and easy maintenance. With those advantages, there is a strong demand for development of small SOFC power generators. The SOFC modules using micro-tube SOFC cells developed this time will for sure satisfy the demand.
The technical development for realizing small SOFC power generation systems is under progress. The SOFC modules, developed this time, are one of the development results and　may indicate the present level of the SOFC development. This technology is one of the watchful technologies

SOUTHBOROUGH, Mass.–Protonex Technology Corporation (LSE: AIM: PTX and PTXU), a leading provider of advanced fuel cell power systems, today announced that the Naval Research Laboratory (NRL), through a program sponsored by the Office of Naval Research (ONR), has documented a flight endurance record on their small, unmanned aerial vehicle (UAV), the Ion Tiger, utilizing a highly advanced fuel cell system from Protonex. The Ion Tiger UAV flew for over 23 hours, setting an unofficial endurance record for fuel cell powered flight, driven by the latest generation of Protonex’ UAV power system.

The 23+ hour duration of the Ion Tiger flight far surpasses the longest previous small UAV flight achieved using any technology. By incorporating the Protonex power system, the Ion Tiger was able to demonstrate seven times the endurance capability of advanced batteries. The Protonex UAV system that was used in the Ion Tiger demonstration is a high performance, ultralight proton exchange membrane [PEM] fuel cell system, coupling stack technology that can achieve 1,000 watts per kilogram with advanced balance of plant components.

With the successful completion of this major milestone, Protonex is planning to continue transitioning this advanced power source into small UAV products with specific payloads and mission requirements for both military and commercial applications. The endurance capabilities proven in this program were previously achievable only with larger scale, more costly UAVs. Protonex is now confident that new critical missions can be achieved by smaller, more cost-effective UAV platforms that incorporate its advanced power systems.

“This impressive 23-hour record flight milestone represents yet another successful collaboration with the NRL and is a culmination of all of our combined efforts to date,” stated Dr. Paul Osenar, Chief Technology Officer, Protonex. “We share the ONR’s vision towards bringing quiet electric propulsion and long endurance to today’s small UAVs and to extend the capability to the warfighter.”

About Protonex Technology Corporation
www.protonex.com
Protonex Technology Corporation develops and manufactures compact, lightweight and high- performance fuel cell systems for portable power applications in the 100 to 1000-watt range. The Company’s fuel cell systems are designed to meet the needs of military, commercial and consumer customers for off-grid applications underserved by existing technologies by providing customizable, stand-alone portable power solutions and systems that may be hybridized with existing power technologies. The Company is headquartered in Southborough, Massachusetts.

• Government encouragement needed
• Civic-sized fuel cell car in ten years
• 2015 milestone for fuel cell cars

Governments need to play a bigger role in the development of a hydrogen fuel infrastructure, according to Honda.

Sachito Fujimoto, project leader for Honda’s hydrogen-powered fuel cell car, the FCX Clarity, told What Car?: ‘There must be support from the Government to encourage the building of a hydrogen fuel infrastructure.’

However, as Fujimoto explained, Honda has not been actively lobbying the EU: ‘It’s difficult for Honda to push the EU, because we’re not a European manufacturer, but Honda has signed a letter of understanding with other car makers to encourage the development of a hydrogen infrastructure.

‘It’s our job to produce the vehicles to prove the business model and to encourage energy suppliers to put the infrastructure in place.’

First fuel cell car in production
Honda’s FCX Clarity is the world’s first production fuel cell car. It’s currently on sale in Japan and in California where it can be leased for $600 a month.

At present, there are around 20 hydrogen filling stations in California, with the state’s lawmakers pushing for more to be built soon.

Fuel cell cars – how they work
Hydrogen gas is stored at high pressure in a fuel tank in the boot of the FCX and fed to a fuel cell stack housed between the front seats. The hydrogen is mixed with oxygen, which creates a reaction that produces electricity to power the car’s motor.

A battery provides additional power and is charged using energy recovered during braking. The only by-product of this process is water, making the FCX a true zero emissions vehicle.

Fujimoto believes that 2015 will be a milestone year for fuel cell cars with many manufacturers set to launch hydrogen powered vehicles. However, he thinks that British buyers will have to wait until around 2020 before they can buy a Civic-sized fuel cell car.