Self-assembling hybrid NiO/Co3O4 ultrathin and mesoporous nanosheets into flower-like architectures for pseudocapacitance

Abstract

The rational design and synthesis of mesoporous hybrid architecture electrode materials for high-performance pseudocapacitor applications still remains a challenge. Herein, we demonstrate the design and fabrication of hybrid NiO/Co₃O₄ flower-like mesoporous architectures on a large-scale for high-performance supercapacitors by a facile, environmentally friendly, and low-cost synthetic method. The as-synthesized hybrid NiO/Co₃O₄ flower-like architectures show a high specific capacitance of 1068 F g⁻¹ at a scan rate of 5 mV s⁻¹ and 1190 F g⁻¹ at a current density of 4 A g⁻¹, a good rate capability even at high current densities and an excellent long-term cycling stability (less than 1% loss of the maximum specific capacitance after 5000 cycles), which can be mainly attributed to their morphological characteristics of mesoporous and ultrathin nanosheets self-assembling into flower-like architectures, as well as a rational composition of the two constituents. The remarkable electrochemical properties, as well as many advantages associated with the synthetic method, should make the present architectures competitive electrode materials for next generation supercapacitors.