Skip to content

Renewable Energy

Clean energy fuel cell that continues to produce power even when the hydrogen has run out

by Adrian Bishop 03 Jul 2012
Clean energy fuel cell that continues to produce power even when the hydrogen has run out

Testing solid-oxide fuel cells. (Photo Credit: Caroline Perry, SEAS Communications.)

A clean energy fuel cell that continues producing power even after its hydrogen fuel is used up has been demonstrated by United States scientists.

The solid-oxide fuel cell (SOFC) generates clean energy by converting hydrogen into electricity. In addition, it can store some electrochemical power that can be used once the hydrogen has run out.

The demonstration, outlined in the latest Nano Letters journal, was carried out by materials scientists from America's Harvard University.

Main investigator Shriram Ramanathan, who is also Associate Professor of Materials Science at Harvard School of Engineering and Applied Sciences (SEAS) says, "This thin-film SOFC takes advantage of recent advances in low-temperature operation to incorporate a new and more versatile material. Vanadium oxide (VOx) at the anode behaves as a multifunctional material, allowing the fuel cell to both generate and store energy."

Left: Each dark speck within the nine white circles at left is a tiny fuel cell. An AA battery is shown for size comparison. (Photo by Caroline Perry, SEAS Communications.) Right: One of the nine circles is magnified in this image, showing the wrinkled surface of the electrochemical membrane

Left: Each dark speck within the nine white circles at left is a tiny fuel cell. An AA battery is shown for size comparison. (Photo by Caroline Perry, SEAS Communications.) Right: One of the nine circles is magnified in this image, showing the wrinkled surface of the electrochemical membrane. (Micrograph by Quentin Van Overmeere.)

Smaller, portable appliances that require light power that can be interrupted, such as unmanned aerial vehicles, could benefit most from the technique, says main author, Quentin Van Overmeere, a postdoctoral fellow at SEAS.

If it is not possible to carry out a refuelling in-situ, using the stored power could increase the appliance's lifespan, he adds.

The team, which includes co-author, SEAS graduate student, Kian Kerman, usually work on thin-film SOFCs with platinum electrodes, but when the anode power runs out, the SOFC can generate just 15 seconds of extra power from the electrochemical reaction.

The latest SOFC has a double layer of platinum and vanadium oxide for the anode that means the cell can keep going without fuel for up to 14 times longer - 3 minutes, 30 seconds - at 0.2 mA/cm2 current density.

Three reactions potentially occur within the new SOFC. The vanadium ions oxodise, hydrogen is stored in the VOx crystal lattice and is released over time and oxodised at the anode and the amount of oxygen ions may differ between the anode and cathode, so oxygen anions may be oxidized as happens in a concentration cell.

operation of the vanadium oxide / platinum fuel cell after its fuel has been spent

Three possible mechanisms (left to right) can explain the operation of the vanadium oxide / platinum fuel cell after its fuel has been spent. The illustration represents a simplified cross-section of the SOFC: the top layer is the cathode (made of porous platinum), the middle layer is the electrolyte (yttria-stabilized zirconia, YSZ), and the bottom layer is the VOx anode. During normal operation, the hydrogen fuel would be at the bottom of this diagram. (Image courtesy of Quentin Van Overmeere.)

All three reactions can feed electrons into a circuit, but it is not known what allows the new fuel cell to keep running. Tests by the team suggest at least two of three mechanisms are simultaneously in play.

But it is early days in developing the reaction and further improvements could be made to the way the VOx-platinum anode is made that could increase the lifespan of the cell. The team believes it could take a couple of years to produce a more advanced SOFC that is ready for testing in applications.

When operating normally, it produces a similar amount of power to a platinum-anode SOFC. Meanwhile, the special nanostructured VOx layer sets up various chemical reactions that continue after the hydrogen fuel is spent.

Purple plasma is visible through the window of this vacuum deposition chamber

Purple plasma is visible through the window of this vacuum deposition chamber. The equipment is used for creating the extremely thin-layered electrodes and electrolyte on a wafer of silicon. (Photo Credit: Caroline Perry, SEAS Communications.)

The research was backed by the U.S. National Science Foundation, a postdoctoral scholarship from Le Fonds de la Recherche Scientifique and the U.S. Department of Defense's National Defense Science and Engineering Graduate Fellowship Program.

The team also received resources from Harvard University Center for Nanoscale Systems and MRSEC Shared Experimental Facilities at MIT, the Massachusetts Institute of Technology.


Trending Eco-Friendly Clothing

Love My Planet Women's Relaxed Fit Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Love My Planet Women's Relaxed Fit Hoodie
Love My Planet women's eco-friendly relaxed fit hoodieSize Guide Centimeters 8 10 12 14 16 18 Bust 84 88 92 97 103 108 Waist 66 70 75 80 85 91 Hips 91 95 99 104 109 116 Bust: Measure around the fullest part of...
£38.00
£38.00
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Penguins Hate Push-Ups men's eco-friendly pullover HoodieSize Guide Centimeters XS S M L XL XXL Height 171 175 179 183 189 195 Chest 86 93 99 104 116 129 Waist 71 76 81 89 99 112 Chest: Measure all round your chest just below...
£38.00
£38.00
Close
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Earth
Quick Add
Close
Notify me
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Lightning Bolt kids eco-friendly long sleeve t-shirtSize Guide Centimeters 3-4yrs 5-6yrs 7-8yrs 9-10yrs 11-12yrs Height 98 112 125 136 147 Chest 60 66 70 75 84 Chest: Measure all around your chest just below your armpits. Height: Your natural height If you fall between...
£18.00
£18.00
Close
Notify me
Notify me
Notify me
Union Jack Tote Bag
Earth
Quick Add
Close
Notify me
Notify me
Union Jack Tote Bag
Union Jack eco-friendly colour tote bagProduct Specification Organic Cotton Tote Bag. Twill Weave (170gsm). 37 x 42 cm (7cm gusset.) Made in India / Designed on the Isle of Wight. Wash Cool, Hang Dry.
£16.00
£16.00
Close
Notify me
Notify me
Prev Post
Next Post

Eco-Friendly Shop

Women's Clothing

Eco-Friendly Clothing for Women Our online shop offers a wide range of sustainable women’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Men's Clothing

Eco-Friendly Clothing for Men Our online shop offers a wide range of sustainable men’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Kids Clothing

Eco-Friendly Clothes for Kids Our online shop offers a wide range of sustainable kids clothing products, including t-shirts, hoodies and jumpers. Our garments...
Shop Now
Someone recently bought a
[time] ago, from [location]

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Earth Times
Sign up for exclusive updates, new arrivals & insider only discounts

Recently Viewed

Edit Option
Back In Stock Notification
this is just a warning
Login
Shopping Cart
0 items

Before you leave...

Take 20% off your first order

20% off

Enter the code below at checkout to get 20% off your first order

CODESALE20

Continue Shopping