Scientists in Stanford University have developed a "smart" lithium-ion battery
that gives ample warning before it overheats and bursts into
flames. The battery is designed for conventional lithium-ion batteries
now used in billions of cellphones, laptops and other electronic
devices, as well as a growing number of cars and airplanes.
Yi Cui, an associate professor of materials science and engineering
at Stanford, said that they wanted to create an early-warning system
that saves lives and property. After incidents such as, fire in two
aircrafts of the Boeing aircraft company in 2013 and short-circuit in
millions of lithium-ion batteries after consumer-laptop the Sony
Corporation in 2006, Cui said, they wanted to lower the odds of a
battery fire to one in a billion or even to zero.
Manufacturing defects, such as particles of metal and dust, can
pierce the separator and trigger shorting, as Sony discovered in 2006.
Shorting can also occur if the battery is charged too fast or when the
temperature is too low – a phenomenon known as overcharge.
To address the problem, Cui and his colleagues applied a nanolayer
of copper onto one side of a polymer separator, creating a novel third
electrode halfway between the anode and the cathode.
The copper layer acted like a sensor that allows you to measure the
voltage difference between the anode and the separator. When the
dendrites grow long enough to reach the copper coating, the voltage
drops to zero. That lets you know that the dendrites have grown halfway
across the battery. It's a warning that the battery should be removed
before the dendrites reach the cathode and cause a short circuit.
You might get a message on your phone telling you that the voltage
has dropped to zero, and the battery needs to be replaced and the
early-warning technology
can also be used in zinc, aluminum and other metal batteries. "It will
work in any battery that would require you to detect a short before it
explodes.
Study was published in the journal Nature Communications.
