'Smart' Battery Now Alerts You Before Overheating


BANGALORE: U.S. Scientists have come up with a developed 'smart' lithium-ion battery that alerts users of potential overheating and fire. The new technology is designed for conventional lithium-ion batteries now used in billions of cell phones, laptops and other electronic devices as well as a growing number of cars and airplanes.

"Our goal is to create an early warning system that saves lives and property," said Yi Cui, associate professor of materials science and engineering at Stanford University. "The system can detect problems that occur during the normal operation of a battery but it does not apply to batteries damaged in a collision or other accident," he informed.

A typical lithium-ion battery usually consists of two tightly packed electrodes which is a carbon anode and a lithium metal-oxide cathode – with an ultrathin polymer separator in between. The separator keeps the electrodes apart. If it's damaged, the battery could short-circuit and ignite the flammable electrolyte solution that shuttles lithium ions back and forth.

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.

The newly developed smart lithium battery possesses a nano-layer of copper on one side of a polymer separator. The copper plays the part of a sensor, enabling the voltage difference between the anode and the separator to be measured. The voltage drops to zero when the aforesaid dendrites touch this third layer.

Also the manufacturers could implement the safety system in such a way that users get a text about the lithium battery in their phones being damaged on their handsets itself, well in advance of the cell bursting into flames.