While graphite is the material of choice for most anodes in lithium-ion batteries, its performance is a limiting factor in making better batteries. Both silicon and tin have already been investigated as high performance alternatives for graphite anodes.
Lorenzo Mangolini – an associate professor at UCR – and his team claim to have shown for the first time that combining silicon and tin into a single composite leads to improvements in battery performance. The nanocomposite is said to triple the charge capacity offered by graphite and to be stable over many charge-discharge cycles.
Mangolini said that adding tin to the silicon, rather than another conductive material such as carbon black, circumvents the low conductivity of silicon without decreasing energy storage.
"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% by weight."
credit: University of California Riverside