Researchers’ “goal is to create an early-warning system that saves lives and property”.
Researchers at Stanford University have created a new ‘smart’ lithium-ion battery that sends an alert to users in case of a potential overheating and fire.
Developed together with the varsity’s materials science and engineering associate professor Yi Cui and colleagues, the new breakthrough plans to target traditional lithium-ion batteries currently powering cellphones, laptops and other electronic devices, even cars and airplanes too.
Cui said: "Our goal is to create an early-warning system that saves lives and property.
"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."
In a bid to avoid short circuit in case of a damaged separator that separates the electrodes in the battery, researchers created a third electrode halfway between the anode and the cathode by adding a nanolayer of copper onto one side of the polymer separator.
Stanford University graduate student, co-author Denys Zhuo said: "The copper layer acts like a sensor that allows you to measure the voltage difference between the anode and the separator.
According to Cui, overcharging causes lithium ions to get wedged on the anode and stack up, leading to formation of lithium metal chains called dendrites.
As soon as the dendrites grow long enough to reach the copper coating, the voltage dives to zero, warning that the battery needs to be replaced before dendrites approach the cathode and finally leading to a short circuit.
Zhuo added: "You might get a message on your phone telling you that the voltage has dropped to zero, so the battery needs to be replaced.
"That would give you plenty of lead time. But when you see smoke or a fire, you have to shut down immediately. You might not have time to escape.
"If you wanted to err on the side of being safer, you could put the copper layer closer to the anode. That would let you know even sooner when a battery is likely to fail."