In-situ Synthesis of Graphene/TiO2 Nanocomposites via Microwave as Anode Materials for Li-ion Batteries

Abstract:

Through the modified household microwave oven system, the graphene-based nanocomposites were in-situ and efficiently synthesized. Results show that the graphene nanosheets can be uniformly generated on the surface of the commercial anatase TiO₂ nanoparticles by microwave-assisted method in a few minutes (the minimum duration is 3 min) through the acute corona discharge of SiO₂/Si. The size of graphene nanosheet is about 50 nm, and few defects can be observed. The crystal structure of anatase TiO₂ remains due to the short production period and low synthesis temperature (600~700 °C). The excellent electrical conductivity of graphene can improve the Li ion diffusion and the electron transport, and decrease the contact resistance at the interface of electrode/electrolyte. The as-prepared graphene/TiO₂ nanocomposite electrode shows a two-fold increase of capacity with good cycling stability under the condition of 1 C (170 mA·g^-1), compared with the traditional TiO₂ nanoparticles. The specific capacity gap of graphene/TiO₂ nanocomposite is substantially widened under different charge-discharge rates (1~5 C), compared with that of the commercial anatase TiO₂ nanoparticles.