U.S. officials grounded Boeing's new 787 Dreamliner because the aircraft's advanced batteries appear to be malfunctioning. But what's the problem? And can it be fixed?
To reduce weight on the plane, Boeing relied
heavily on lithium ion batteries -- the same type found in mobile phones
and laptops.
While these batteries can produce a lot of power
for their weight, they're also prone to problems. It was these same
batteries that caught fire in laptops a few years back and, more
recently, were suspected culprits in electric car fires.
How they work: Ions from the
element lithium tease out energy from the battery's electrodes,
according to Donald Sadoway, a materials chemistry professor at the
Massachusetts Institute of Technology.
This is different from other types of batteries
commonly used in electronics, which use a combination of nickel and
cadmium or lead and acid, among other things.
Why they're better: Lithium is
the lightest of all metals, so its ions hold energy more efficiently --
more than twice as much per unit of weight as nickel cadmium batteries.
This made the batteries attractive for Boeing (BA, Fortune 500),
which used them to electronically assist some of the functions that
were previously performed using hydraulics. A lighter plane is more fuel
efficient, which is one of the main selling points for the 787. Other
aircraft makers have also been using more lithium ion batteries.
