Lithiation of Silicon Nanoclusters

Engineering better batteries for mobile electronics is a major endeavor in energy research. Silicon is potentially a great anode material for lithium-ion systems, but unfortunately it undergoes dramatic volume changes during lithiation and delithiation, leading to rapidly fading ability to hold a charge. The authors show that lithiation of amorphous silicon nanoclusters is a two-stage process governed by Coulomb repulsion, and that at high loading the Li atoms switch where they like to reside in the clusters, causing expansion. Knowing the physics of this threshold allows for optimized battery design.