Lithium-ion rechargeable batteries have been on the
market for a long time and are prone to problems. The batteries, for
instance, were the cause of massive recall several years ago after
they were overheating in notebooks which in turn caused fires. One of
the more promising new battery technologies being researched are
These batteries are cheaper and have a
significantly larger capacity for storing energy than existing
lithium-ion batteries. Physorg reports that the average
lithium-ion battery stores only a third of the energy that zinc-air
batteries are capable of storing and cost about twice as much as the
A Swiss company called ReVolt plans to
release a zinc-air battery next year. At first, the batteries will be
small units that will be used in hearing aids. Later the batteries
will come in larger forms for mobile phones and much later, the
zinc-air battery will find its way into electric vehicles.
zinc-air battery was developed by a firm called SINTEF in Norway and
ReVolt was formed to market the battery. In a zinc-air battery,
oxygen from room air is used to generate current. The air is used as
an electrode and the battery contains an electrolyte and a zinc
electrode in a casing that is porous and allows air inside. The
zinc-air battery is much safer than lithium-ion batteries because
there are no volatile materials inside the battery that could
possibly catch fire.
The zinc-air battery produces electricity
when the air electrode is discharged with the help of catalysts
producing hydroxyl ions in the aqueous electrode. The zinc electrode
then gets oxidized and releases electrons to form an electric
current. When the battery is recharged, the process happens in
reverse and oxygen is released into the air electrode.
challenge for the researchers was to devise a method where the air
electrolyte wasn’t deactivated in the recharging cycle to the point
where the oxidation reaction slowed or stopped. The slowing or
stopping of the oxidation reaction reduced the number of times that
the zinc-air battery could be recharged.
reports that prototypes of the zinc-air battery have been tested
through more than a hundred charge and discharge cycles. ReVolt hopes
to increase the number of charge and discharge cycles to the 300 to
500 range. That number would make the batteries useful for cell
phones and other electronic items that are recharged frequently.
zinc-air batteries ReVolt is working on are also being developed for
future use in electric vehicles. Before that point can be reached the
batteries have to reach the point of being able to withstand up to
10,000 charge cycles.