The lithium-ion batteries that power everything from smartphones to electric vehicles carry a relatively low individual chance of failure, but the sheer quantity in use everyday means the risk of something going horribly wrong somewhere in the world is quite real. Looking to safeguard against such events, a team of scientists has developed a smart chip that can be embedded inside these batteries to monitor their health, offering a warning when it is at risk of catching fire or exploding.
Today's lithium-ion batteries come equipped with a chip that keeps tabs on voltage, temperature and an estimate of the amount of charge they are holding. This enables warning systems that alerts users if if the battery is overheating, just like the temperature alert that appears on screen when an iPhone is left directly in the sun on a warm day.
But according to Professor Rachid Yazami of the Energy Research Institute at Nanyang Technological University in Singapore, what these current chips are lacking is the ability to detect malfunctions, which leaves the door ajar for potentially dangerous battery failures.
"This poses a serious risk for electric vehicles and even in advanced aeroplanes as usually big battery packs have hundreds of cells or more bundled together to power the vehicle or aircraft," he says. "If there is a chemical fire caused by a single failed battery, it could cause fires in nearby batteries, leading to an explosion."
Yazami, who actually invented the graphite anode used in lithium-ion batteries, has led the development of a new and improved chip that more precisely monitors the state of the charge of the battery, along with its health. This is done through a proprietary algorithm based on electrochemical thermodynamics measurements. The data is presented as a three-dimensional chart, which is said to resemble a ski route running down a mountain.
"The 'ski route' of a brand new battery looks different from those of a degraded or faulty battery – just like how two fingerprints will look quite different," explains Yazami. "In addition to knowing the degradation of batteries, our technology can also tell the exact state of charge of the battery, and thus optimize the charging so the battery can be maintained in its best condition while being charged faster."
The team says the new chip is small and versatile enough to be embedded in almost all kinds of batteries, from those in mobile devices to huge power packs in electric vehicles and advanced aeroplanes. It has been under development for five years and Yazami's startup KVI is now working on building it into commercial products. To begin with, these will include external battery packs for mobile devices and charge gauges for electric vehicles.
"My vision for the future is that every battery will have this chip, which will in turn reduce the risk of battery fires in electronic devices and electric vehicles while extending their life span," he says.
Source: Nanyang Technological University