Researchers at Stanford University, led by William Chueh, have developed a new technique that can extend the service life of lithium-ion batteries by 50%, without altering their chemical structure. The breakthrough, reported in New Scientist, could significantly improve the longevity of electric vehicle batteries and stationary energy storage systems.
The new method involves a modification in the manufacturing process, specifically the first charge cycle. Traditionally, new batteries are charged slowly over several hours at a low voltage.
However, the researchers discovered that charging with a high current during the initial cycle can significantly enhance the battery's long-term performance. “The cool thing is that we didn't change any chemistry of the battery. We just changed that last step in manufacturing to form the battery a little differently,” Chueh said.
The process was optimized using machine learning, which identified that the charging current during the first cycle was a critical factor. High current at the outset leads to the deactivation of more lithium ions, creating extra space in the positive electrode. This adjustment improves the efficiency of charging and discharging and slows the overall degradation of the battery.
The new method could extend the lifespan of lithium-ion batteries in electric vehicles from 1,500 charging cycles to over 2,000, offering potential cost and environmental benefits.
