An Israeli company called Phinergy has retrospectively fitted a Citroën C1 with a metal-air battery to run the car for up to 1000 miles just by topping it up with water. There is a lithium-ion battery also in the boot of the car that acts as the primary power source for the first 100 miles, with the aluminium-air battery acting as a range extender.
The metal-air battery has aluminium plates serving as an anode and the air is the cathode. The driver simply tops the car up with water via the traditional petrol point to replenish the electrolyte. The lithium-ion battery can be charged from the mains so the vehicle only requires the use of the aluminium-air battery after the initial 200 miles.
The aluminium itself is converted into electricity through oxidisation, which means the battery is not rechargeable – each battery gives 1000 miles of driving, after which the plates need replacing. The cost of replacing plates has not been disclosed, but with aluminium priced at US$2 a kilo, it may be more cost effective than petrol. The recycling process of aluminium would have to be factored in to the plate costs.
The car has successfully been test driven and will be assessed to determine marketability.
More info at www.phinergy.com