(286h) Graphene Oxide Based Foams for Lithium Ion Batteries

Advances in science and engineering related to emerging technologies for lithium-ion batteries (LIBs) have been so spectacular in recent years that they have become the most popular source for portable computing and telecommunication equipment.  In the last five years there has been a lot of work on the electrochemical properties of electrode Materials for Lithium Ion Batteries (LIB) using Graphene (G) and Graphene Oxide (GO) with silicon , however, these works present several drawbacks associated with the breakage of the silicon layer. We present a new technology that avoids breakage of the silicon layer at the SEI interface and their characterization. We incorporate silicon as the high capacity electrochemically active material which has the potential to greatly increase the capacity of these materials. We thermally reduce these composites to convert GO to a graphitic structure  providing high electrical conductivity as well as high lithium ion conductivity. The uniform cellular structure of these foams provides a method to obtain a uniform dispersion of the active material inside the composites.  We solidify the composite to effectively trap the electrochemically active nanoparticles within the foam preventing segregation of the active components from the conductive matrix.   This work also focuses on using the matrix to create a barrier between the active component and the electrolyte.  Such a barrier, even only a few nanometers in thickness, has the potential to limit the inefficiencies created by the breaking and reformation of the solid electrolyte interface upon cycling.   This allows high capacity active materials to be used with improved cycling stability, efficiency, and power.   Our results show anodes cycled at very high charge and discharge rates of 3A/g are possible.  At these rates capacities over 800 mA-hr/g were demonstrated at 40 cycles.