Alternative fuel cells

ACAL Energy, a UK developer of low-cost proton exchange membrane (PEM) fuel cells, is preparing to commercialise an inexpensive, platinum-free liquid cathode technology.

The new technology, called FlowCath, could help make PEM fuel cells a viable alternative to combustion engines.

PEM fuel cells generate electricity by using an electrochemical reaction that combines oxygen and hydrogen. Each cell consists of two electrodes that are separated by a thin polymer membrane that carries electrically charged particles between the two electrodes.

PEM cells operate at low temperatures that would normally make electrochemical reactions extremely slow, so the processes are often catalysed by a thin layer of platinum on each electrode.

One of the biggest challenges for PEM fuel cell developers has been finding an alternative for platinum, which is expensive. ACAL Energy claims its new platinum-free liquid cathode technology can perform at levels competitive with conventional fuel cells.

ACAL Energy revealed that its prototype fuel cells can obtain peak power density of more than 570mW/cm2. The cells were able to produce this kind of power consistently since testing began late December 2008.

The goal now is to improve power to more than 1W/cm2 in 2009.

The technological development follows a £3.3m investment from a host of partners led by the RisingStars Growth Fund. The fund, managed by UK venture capitalist Enterprise Ventures, invests in early stage technology companies that have the potential to grow into successful international operations.

‘This is a very significant achievement and clearly demonstrates that ACAL Energy’s liquid cathode technology will deliver performance that compares very well with conventional platinum fuel cells as a much lower cost and improved reliability,’ said SB Cha, chief executive of ACAL Energy. ‘I congratulate our technical team and Dr Andy Creeth, our chief technical officer, on this impressive achievement.’