California start-up claims fuel cell breakthrough

A California start-up company has made an advance that it claims will make Direct Methanol Fuel Cells (DMFCs) - envisaged as a future power source for mobile electronics devices - smaller, cheaper and lighter.

PolyFuel's development of a new DMFC membrane comes as several of the world's largest electronics companies are developing fuel cells with a view to commercialising them later this year or next year.

The membrane is a small piece of plastic that looks something like sandwich wrap, according to PolyFuel president and CEO, Jim Balcom.

It sits at the heart of the DMFC separating a mixture of methanol and water from a catalyst.

The electrical potential across the membrane wass the key to power creation, however, the current most popular membrane wasn't well suited for use in DMFC applications, Balcom said.

"Until now all of the manufacturers, and we've counted 35 organisations working on DMFCs, have been hampered because they have had to use a hydrogen fuel cell membrane that was developed 40 years ago," he said. "It has been the only one available for DMFC applications and they are very different technologies."

The biggest problem developers have is stopping methanol crossing over the membrane - something that lowers overall efficiency of the fuel cell because fuel is wasted and it also results in generation of heat. To combat this problem researchers have kept methanol concentrations relatively low, at around 10 per cent although a higher concentration would be better, said Balcom.

His company's new membrane allowed for much higher concentrations - between 50 per cent and 100 per cent - and this should mean DMFCs could be made one-third smaller, lighter and less expensive, he said.

Increasing the methanol concentration has been a stated goal of several companies developing DMFCs for some time.

NEC, which plans to commercialise a DMFC for notebook computers this year, is currently using a methanol concentration of around 10 per cent in its prototype.

Toshiba, which has shown a prototype battery charger based on DMFC technology, said it used a concentration of between 3 per cent and 6 per cent.

Hitachi plans a DFMC for use in personal digital assistants (PDAs) and said it hoped to raise methanol concentration from around 20 per cent to 30 per cent by the time the produce was commercialised in 2005.

PolyFuel's new membrane wass already in sample production and initial feedback from the company's potential clients was good, Balcom said.

The company's current production capacity in Silicon Valley was anticipated to be enough to handle customer demand though 2005 and further expansion would be based on demand, he said.