LAUSR

A multiwall carbon nanotube/graphene (MWCNT/GR) composite was synthesized for an enhanced supercapacitor. Aerosol spray drying (ASD) was used to synthesize the MWCNT/GR particles using a mixture of graphene oxide (GO) solution and MWCNT. The effect of the MWCNT/GO ratio on the properties of the composite, including its shape and structure, was investigated. The composite particles were generally shaped like a crumpled paper ball, with an average diameter of approximately 5 µm. The MWCNTs, which were uniformly dispersed among the graphene sheets, not only increased the basal spacing of the sheets but also bridged the wide gaps between them, thereby improving electron transfer between the layers. Thus, the MWCNTs increased the contact area of the electrolyte/electrode and facilitated the transportation of electrons and electrolyte in the electrode. Using a two-electrode testing system, the electrochemical results demonstrate that the MWCNT/GR (weight ratio = 0.1) electrode has a capacitance of 192 F g–1 and an excellent rate of capacity retention (88% at 4 A g–1).