Ionic liquid-assisted synthesis of rGO wrapped three-dimensional CuS ordered nanoerythrocytes with enhanced performance for asymmetric supercapacitors

Abstract rGO wrapped three-dimensional (3D) CuS ordered nanoerythrocytes (CuS-OEs/rGO) were fabricated in the presence of ionic liquid ([BMIm]Cl) and GO under solvothermal conditions and investigated as electrode materials for supercapacitors. CuS-OEs/rGO exhibited high specific capacity, good rate capability, and excellent cycling stability, compared with two-dimensional (2D) CuS disordered nanoplates/rGO (CuS-DPs/rGO) and three-dimensional (3D) CuS disordered nanoflowers (CuS-DFs). Furthermore, CuS-OEs/rGO based asymmetric supercapacitor displayed impressive rate performance (retain 69.8% at 10 A g −1 ), outstanding cyclability (capacitance retention of 90.8% after 10000 cycles at 2 A g −1 ), and high-energy density (16.7 Wh kg −1 at a power density of 681 W kg −1 ).