Miniaturisation of Fuel Cells Improves Prospects of Technology Commercialisation

September 29, 2005

To create a compelling microfuel cell technology, scientists have to look at providing power densities that are comparable to that of conventional or rechargeable batteries. Direct methanol fuel cell (DMFC), a popular fuel cell technology, only provides power density in the range of 20 to 50 mille watts per square cm (mW/cm2).

DMFCs will have to reach 100 mW/cm2 to avoid an output density shortfall and to meet the requirements of power-hungry devices such as notebook computers, handheld data collection devices and military equipment.

A DMFC needs a pump and pipes to carry out electrochemical processes. This creates space constraints and it becomes difficult to mount the system on a miniature scale.

A very effective alternative to DFMC is the direct formic acid fuel cell (DFAFC) technology, with five to six times higher power densities. Such high densities aid the miniaturisation of the fuel cells, especially in portable devices. They also improve the efficiency of the fuel cell without compromising on the net output of electricity.

“The use of formic acid as a fuel offers advantages such as less fuel cross-over, use of higher fuel concentrations (80 per cent by weight) at the anode side, good anode kinetics at room temperatures and high power densities,” says Frost & Sullivan Research Analyst Viswanathan Krishnan.

Researchers from Kongkuin University, Japan have worked and improved upon direct borohydride fuel cells (DBFCs) to eliminate or reduce glitches such as borohydride crossover by using a Nafion membrane electrolyte-based fuel cell. They claim to have achieved a power density of 160mW/cm2 at an operating temperature of 70 degree centigrade.

Taking this further, researchers at the Solid State and Structural Chemistry Unit of Indian Institute of Science, India have proposed a DBFC using hydrogen peroxide as the oxidant. The research team reports power density of 350mW/cm2 at a cell voltage of 1.2 V.

To generate this electricity, it is important to have catalysts to speed up the electrochemical process. Currently, only platinum and ruthenium are used in the fuel cells as catalysts. Scientists have been working on finding non-noble substitutes that are more cost-efficient for fuel cell technology.

“Scientists are considering nanomaterials as catalysts for fuel cells consisting of carbon-supported metal particles,” notes Krishnan. “The nanomaterial structure increases the surface-to-volume ratio of expensive noble metals and plays a vital role in reducing the overall cost of the fuel cell.”

At the University of Oxford, researchers have suggested using an enzyme catalyst within a fuel cell. Instead of the regular platinum-coated anode, they have used hydrogenase-coated electrode to catalyse efficient oxidation of hydrogen. The cathode contains the fungal enzyme laccase, which catalyses reduction of oxygen to water.

Microfuel cells have been taking giant strides in technology development. Newer designs that give them greater power and efficiency have firmly placed them on the path to commercialisation.

Explore further: Hydrogen power moves a step closer

Related Stories

Hydrogen power moves a step closer

September 14, 2017

Physicists at Lancaster University are developing methods of creating renewable fuel from water using quantum technology.

Army scientists discover power in urine

September 12, 2017

Scientists at the U.S. Army Research Laboratory observed an unexpected result when combining urine with a newly engineered nano-powder based on aluminum. It instantly releases hydrogen from the urine at much higher rate than ...

Converting waste toilet paper into electricity

September 12, 2017

Chemists at the University of Amsterdam's (UvA) Sustainable Chemistry research priority area, together with colleagues from the Copernicus Institute of Sustainable Development of Utrecht University, have published the first ...

CO2-free mobility: (how) is that possible?

September 11, 2017

Right now, everyone is talking about mobility, how it ought to be CO2 -neutral and clean. Yet how do we get there? Banning combustion engines, changing how we usually get around or gradually shifting towards electric vehicles ...

Recommended for you

What do we need to know to mine an asteroid?

September 19, 2017

The mining of resources contained in asteroids, for use as propellant, building materials or in life-support systems, has the potential to revolutionise exploration of our Solar System. To make this concept a reality, we ...

The cosmic water trail uncovered by Herschel

September 19, 2017

During almost four years of observing the cosmos, the Herschel Space Observatory traced out the presence of water. With its unprecedented sensitivity and spectral resolution at key wavelengths, Herschel revealed this crucial ...

Nonlinear physics bridges thoughts to sounds in birdsong

September 19, 2017

The beautiful sound of birdsongs emerging from the trees is a wonderful example of how much nature can still teach us, even as much about their origins are still mysterious to us. About 40 percent of bird species learn to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.