California start-up claims fuel cell breakthrough

A California start-up company has claimed that its direct methanol fuel cell membrane will make the cells - envisaged as a future...

A California start-up company has claimed that its direct methanol fuel cell membrane will make the cells - envisaged as a future power source for mobile electronics devices - smaller, cheaper and lighter.

PolyFuel's development of a DMFC membrane comes as several of the world's largest electronics companies are developing fuel cells with a view to commercialising them in the next couple of years.

The membrane is a small piece of plastic, resembling cellophane wrap, which sits at the heart of the DMFC separating a mixture of methanol and water from a catalyst. The electrical potential across the membrane that is the key to power creation.

"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. It has been the only one available for DMFC applications and they are very different technologies," said PolyFuel president and chief executive officer Jim Balcom.

The biggest problem developers have is stopping methanol crossing over the membrane, something that reduces 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 at around 10% although a higher concentration would be better, said Balcom.

PolyFuel's membrane allows for much higher concentrations - between 50% and 100% - and this should mean DMFCs can be made one-third smaller, lighter and less expensive, he claimed.

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

NEC, which plans to commercialise a DMFC for notebook computers this year, is using a methanol concentration of around 10% in its prototype, and Toshiba, which has shown a prototype battery charger based on DMFC technology, says it uses a concentration of between 3% and 6%.

Hitachi plans a DFMC for use in PDAs and said it hoped to raise methanol concentration from around 20% to 30% by the time the produce is commercialised in 2005.

PolyFuel's membrane is already in sample production and Balcom said initial feedback from the company's potential clients had been good so far. The company's production capacity in Silicon Valley is anticipated to be enough to handle customer demand though 2005 and further expansion will be based on demand, he added.

Martyn Williams writes for IDG News Service

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