In a step that could help boost the range of electric vehicles and performance of electronic devices, a U. research team has found a way to revitalize rechargeable lithium batteries, the German news agency reported.
As lithium batteries cycle, they accumulate little islands of inactive lithium that are cut off from the electrodes, decreasing the battery's capacity to store charge. But a research team from the SLAC National Accelerator Laboratory and Stanford University, discovered that they could make this "dead" lithium creep like a worm toward one of the electrodes until it reconnects, partially reversing the unwanted process.
According to the researchers, this extra step slowed the degradation of their test battery and increased its lifetime by nearly 30 percent. "We are now exploring the potential recovery of lost capacity in lithium-ion batteries," the TechXplore website quoted Stanford researcher Fang Liu as saying. The new technique aims at making rechargeable batteries with lighter weight, longer lifetimes, improved safety, and faster charging speeds.
During the study published in the journal Nature, the researchers discovered that the isolated lithium island wasn't "dead" at all but responded to battery operations. When charging the cell, the island slowly moved towards the cathode; when discharging, it crept in the opposite direction.
"It's like a very slow worm that inches its head forward and pulls its tail in to move nanometer by nanometer," the researchers said. "In this case, it transports by dissolving away on one end and depositing material to the other end. If we can keep the lithium worm moving, it will eventually touch the anode and reestablish the electrical connection," Liu said. Our findings also have wide implications for the design and development of more robust lithium-metal batteries in the future, she concluded.