Rational synthesis of porous CuO/Cu 2 O/NiCo 2 O 4 3D composites for high-performance supercapacitors

Bimetallic oxide NiCo2O4 and its composites hold promising applications for supercapacitors owing to their theoretical capacity, inexpensiveness, and ease of synthesis. In this work, novel CuO/Cu2O/NiCo2O4 (CCNC) open-structured three-dimensional (3D) composites were synthesized. The multiple components and open structure of the composite provide many open channels for ion diffusion, thus, promoting good rate performance during the electrochemical reaction. The optimized sample (CCNC3–6) shows good electrochemical performance, with a high specific capacitance of 1614 F g−1 at a current density of 1 A g−1, and good rate performance by maintaining a capacitance of 1383 F g−1 for increasing current density to 20 A g−1 (with a merely 14% capacitance loss, as compared with that at 1 A g−1). The composite also shows enhanced cycle stability than pure NiCo2O4, with 81% remaining capacitance after 3000 cycles. The CCNC 3D nanocomposites are demonstrated to be promising for high-performance supercapacitor applications.