Researchers in the United States have discovered a simple method of extending the lifespan of lithium-ion batteries by as much as 50 per cent. In a study published in late August in the journal , researchers from the SLAC-Stanford Battery Center in the United States discovered that charging lithium-ion batteries at high currents just before they leave the factory can increase their average lifespan by 50 per cent. Using scientific machine learning, a type of artificial intelligence (AI), the researchers were able to determine the why behind the discovery.
The study, ‘ ’, was also described in an article , which outlined the discovery and the ways in which it may help to optimise battery manufacturing. When a battery first leaves the factory, the positive electrode of a newly minted battery is 100% full of lithium, but every time a battery goes through a charge-discharge cycle, some of the lithium is deactivated. According to one of the researchers, Xiao Cui, minimising the lithium deactivation losses is key in prolonging the battery’s working lifespan.
The first charge a lithium-ion goes through causes the creation of a layer called the solid electrolyte interphase (SEI) that forms on the surface of the negative electrode during the first charge. Subsequently, the SEI layer protects the negative electrode from side reactions that would otherwise accelerate the lithium loss and accelerate the battery’s degradation. Getting this SEI layer just right is therefore vitally.