Ultrathin 5 μm Thick Silicon Nanowires Intercalated with Reduced Graphene Oxide Binderless Anode for Lithium-Ion Batteries

Binderless carbon-based anode films can enhance the energy density of lithium-ion batteries; however, a major challenge is their long-term electrochemical performance stability. Herein we report ultrathin binderless anodes based on synthesized stacks of reduced multilayer graphene-oxide and silicon nanowires. A key innovation in this work is that instead of using graphene-oxide films based on disordered graphene flakes derived from chemical exfoliation, we produce large and well-ordered sheets of multilayer reduced graphene oxide by chemical vapor deposition, resulting in stronger graphene multilayers with thicknesses of ∼700 nm. The binderless anodes are prepared by building a stack of chemical vapor deposition multilayer graphene oxide with a radio-frequency-sputtered silicon coating followed by thermal annealing for the simultaneous reduction of graphene and silicon nanowire growth. This novel composition results in ∼5 μm ultrathin anodes with a specific capacity of 2247 mAh/g and a capacity retention of 842 mAh/g after 90 cycles.