Yesterday the internet was abuzz with the news that a Lexus Hybrid SUV malfunctioned and exploded.
The tragic news turned out to be incorrect. The Lexus SUV did explode, but not because of a malfunction, but because of a bomb that severely injured Dr. Trent Pierce of West Memphis, Arkansas.
But some questions still linger. Can hybrid or electric cars explode?
According to Consumer Reports,
"Ford, Honda, and Toyota use nickel-metal hydride (NiMH) batteries,
which the Honda Emergency Response Guide for Hybrid Vehicles claims are
"non-flammable" and "non-explosive." The batteries are sealed in a
protective metal case and insulated from the vehicle body. Toyota and
Honda locate the battery packs near the rear axle, a spot they say is
well-protected in the event of a collision."
The current generation of batteries used in hybrid cars (nickel metal hydride cells) are non-explosive. However the newest all electric cars like the Tesla Roadster, which uses 6,831 lithium ion cells (the same cells that run a laptop computer) in theory can explode. Lithium ion batteries are more energy-dense than nickel metal hydride cell and thus provide a more efficient power source.
This means a lithium ion battery can run at a higher power for a longer time than a nickel metal battery of the same weight.
However most lithium cells use a cobalt oxide chemistry that can catch fire or
explode if the battery is charged or discharged too quickly, or if it
is physically damaged.
The Tesla Roadster has passed the U.N. battery test. Tesla is quick to point out that it has built in many safety features to keep the batteries from exploding.
According to CNET news in order for Tesla Roadster to get the U.N. battery certification:
The batteries are deliberately short-circuited and placed on shaking
tables. The company also did some puncture testing. Even if one cell
blows, the battery pack is designed so that it won't burst into what
the lithium ion industry quaintly calls "a runaway thermal reaction."
That exploding Dell notebook? That was a runaway reaction.
Several Tesla Roadsters have already been in involved in accidents without incident.