Synthesis of rGO/PS compound with sandwich structure on Ni foam as binder-free electrode for supercapacitor

Here, we demonstrate the design of a binder-free reduced graphene oxide (rGO) and polystyrene colloidal microsphere ( PS) compound with rGO/PS/rGO sandwich structure and application for supercapacitors electrode. rGO and PS are alternately deposited into 3D Ni foam by a simple layer-by-layer assembly based on dip-coating. The interlayer space of rGO film expanded by PS microsphere and 3D structure of compound electrode can effectively shorten diffusion pathways of ions and accelerate the transport of ions into graphene sheets. The resulting rGO/PS compound electrode exhibits a high specific capacitance with 164.7 F g(-1), and outstanding rate capability. It is found that the specific capacitance is dependent on the number of rGO film layers in rGO/ PS compound electrode.