Three.dimensional porous carbon nanotubes.reduced graphene oxide composite aerogel for high.performance symmetrical supercapacitor

Carbon nanotubes- reduced graphene oxide (CNTs-rGO) three-dimensional aerogels were prepared using hydroxylated carbon nanotubes (CNT- OH) and graphene oxide ( GO) as raw materials through redox self- assembly hydrothermal synthesis strategy. The effect of hydrothermal temperature on three- dimensional aerogels was investigated. The structure and morphology of the materials were characterized by scanning electron microscopy (SEM), X- ray diffraction (XRD), Raman spectroscopy (Raman) and X- ray photoelectron spectroscopy ( XPS). The electrochemical test results indicate that the aerogel CNTs- rGO synthesized at 140. showed the best electrochemical performance, the specific capacitance at 1 A center dot g(-1) current density was up to 294.65 F center dot g(-1), and the shape of cyclic voltammetry curve at 50 mV center dot s(-1) scanning speed was still similar to a rectangle, showing good reversibility. The assembled symmetrical supercapacitor had a maximum energy density of 3.744 Wh center dot kg(-1) at a power density of 249.8 W center dot kg(-1). After 10 000 cycles at 1 A center dot g(-1), its capacitance retention and Coulombic efficiency were both about 100%. The excellent electrochemical performance is mainly attributed to the porous three - dimensional structure ofCNTs- rGO composite material, which ensures rapid ion transport. Carbon nanotubes can not only overcome the sheet stacking problem of graphene, but also increase the specific surface area of the composite material, increase the reactive sites, and improve its electrochemical properties; at the same time, it can also provide electron transport channels and improve the conductivity of the material, so that the composite material has better mechanical and electrochemical properties.