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.