Both silicon and tin have been investigated as high-performance alternatives for graphite anodes in lithium ion batteries, but the group led by Lorenzo Mangolini, an associate professor of mechanical engineering and materials science and engineering in UCR’s Bourns College of Engineering, showed for the first time that combining both materials into a single composite leads to dramatic improvements in battery performance. In addition to tripling the charge capacity of a graphite anode, the silicon-tin nanocomposite is stable over many charge-discharge cycles, extending its useful life. The manufacturing process is also simple as only 2% tin is needed.
“Lithium-ion batteries are growing in popularity for electric vehicles and aerospace applications, but there is a clear need to alleviate range anxiety—the fear that a vehicle won’t have enough charge to reach its destination—before we will see large-scale adoption. Any technology that can help is welcome, as long as it is simple and scalable, and our technology meets both those criteria,” said Mangolini. “The synergistic effects between these two materials lead to batteries that exceed the performance of each of the two components alone, an improvement that is a result of the high electrical conductivity and good energy storage capacity of tin. This can be achieved with the addition of even minor amounts of tin, as small as 2 percent by weight,” he said.