Preparation of Three-Dimensional Co₃O₄/Graphene Composite for High-Performance Supercapacitors

Abstract

Here, we developed a simple and efficient route for preparation of three-dimensional (3D) Co₃O₄-anchored graphene composites using sacrificial template-assisted method and subsequent deposition process of Co₃O₄ nanoparticles. As structural guiding materials, polystyrene spheres provide 3D porous architectures with a high surface area. 3D porous graphene materials serve as conductive supporters for deposition of Co₃O₄ nanoparticles through precipitation growth. The 3D porous composite structures of Co₃O₄/graphene composites were intensively investigated using scanning electron microscope, transmission electron microscope, and X-ray diffraction. The 3D Co₃O₄/graphene composites show a high specific capacitance 328 F g⁻¹ with efficient and fast charge-discharge process in aqueous 6 M KOH electrolyte. In addition, the composites provide a good cycle lifetime, which retained 98% capacitance retention over 2000 cycles.