The new concept combines the best aspects of hydrogen fuel cells with battery-based electrical power.
The proton flow battery concept eliminates the need for the production, storage and recovery of hydrogen gas, which currently limit the efficiency of conventional hydrogen-based electrical energy storage systems.
"As only an inflow of water is needed in charge mode - and air in discharge mode - we have called our new system the 'proton flow battery'," explained lead researcher, Associate Professor John Andrews, from RMIT's School of Aerospace, Mechanical and Manufacturing Engineering. "Powering batteries with protons has the potential to be a much more economical device than using lithium ions, which have to be produced from relatively scarce mineral, brine or clay resources".
"Hydrogen has great potential as a clean power source and this research advances the possibilities for its widespread use in a range of applications - from consumer electronic devices to large electricity grid storage and electric vehicles."
RMIT's concept integrates a metal hydride storage electrode into a reversible proton exchange membrane (PEM) fuel cell.
During charging, protons produced from splitting water are directly combined with electrons and metal particles in one electrode of a fuel cell, forming a solid-state metal hydride as the energy storage. To resupply electricity, this process is reversed.
Published in the International Journal of Hydrogen Energy (January, 2014), the research found that, in principle, the energy efficiency of the proton flow battery could be as high as that of a lithium ion battery, while storing more energy per unit mass and volume.
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