A Cr2O3/MWCNTs composite as a superior electrode material for supercapacitor

It has been a challenge to achieve a good capacitive performance for Cr-based oxides, and only few studies have been reported on these oxides. Herein, a composite of chromium oxide (Cr2O3) and multi-walled carbon nanotubes (MWCNTs) was prepared by a simple hydrothermal procedure followed by thermal decomposition. The Cr2O3 nanoparticles were evenly decorated on the surface of MWCNTs. The prepared Cr2O3/MWCNTs composite exhibited superior electrochemical performance in a 1 M KOH electrolyte, i.e., 257 F g(-1) at the current density of 0.25 A g(-1), and the capacity fade was only 12% after 3000 cycles. In addition, the Cr2O3/MWCNTs//AC asymmetric capacitor has high energy density (15.2 W h kg(-1) at 266 W kg(-1)). The abovementioned results for the first time indicate the potential application of Cr2O3 as an electrode material for supercapacitors.