Amphiphilic ligand exchange reaction-induced supercapacitor electrodes with high volumetric and scalable areal capacitances

Abstract

We introduce high-performance supercapacitor electrodes with ternary components prepared from consecutive amphiphilic ligand-exchange-based layer-by-layer (LbL) assembly among amine-functionalized multi-walled carbon nanotubes (NH2-MWCNTs) in alcohol, oleic acid-stabilized Fe3O4 nanoparticles (OA-Fe3O4 NPs) in toluene, and semiconducting polymers (PEDOT: PSS) in water. The periodic insertion of semiconducting polymers within the (OA-Fe3O4 NP/NH2-MWCNT)(n) multilayer-coated indium tin oxide (ITO) electrode enhanced the volumetric and areal capacitances up to 408 +/- 4 F cm(-3) and 8.79 +/- 0.06 mF cm(-2) at 5 mV s(-1), respectively, allowing excellent cycling stability (98.8% of the initial capacitance after 5000 cycles) and good rate capability. These values were higher than those of the OA-Fe3O4 NP/NH2-MWCNT multilayered electrode without semiconducting polymer linkers (volumetric capacitance similar to 241 +/- 4 F cm(-3) and areal capacitance similar to 1.95 +/- 0.03 mF cm(-2)) at the same scan rate. Furthermore, when the asymmetric supercapacitor cells (ASCs) were prepared using OA-Fe3O4 NP-and OA-MnO NP-based ternary component electrodes, they displayed high volumetric energy (0.36 mW h cm(-3)) and power densities (820 mW cm(-3)). (C) 2018 Elsevier B. V. All rights reserved.