Lithium silicide encapsulated porous carbon thin films for lithium ion batteries

Abstract

Improved energy storage is a critical component of reaching an energy-sustainable future. Lithium ion batteries are very promising due to their relatively high energy density, slow loss of charge when idle, and essentially no memory effect. However, their charge capacity, cyclability, and energy and power densities need to be improved to meet our energy demands. In order to accomplish this goal, new electrode materials are being investigated. Silicon is promising in that it has a charge capacity six times higher than graphite, the currently used material; however, silicon has poor cyclability due to its extreme volumetric expansion during lithiation, which causes a loss of electrical contact and a cyclic gain and loss of a solid-electrolyte interface (SEI).