Network-like mesoporous NiCo2O4 grown on carbon cloth for high-performance pseudocapacitors

Abstract

Network-like mesoporous NiCo₂O₄ arrays were grown on flexible carbon cloth via a hydrothermal method first assisted by polyethylene oxide – polypropylene oxide – polyethylene oxide and ethylene glycol followed by thermal treatment. These arrays were made up of nanoflakes (thickness varies from 5 to 15 nm) and multilevel pores, giving a vast specific surface area of 130.2 m² g⁻¹. The as-prepared products were fabricated into electrodes to conduct electrochemical experiments. The results showed a high capacitance of 1843.3 F g⁻¹ (volume capacitance of 33.8 F cm⁻³) at 1 A g⁻¹, satisfied constant rate performance of 80% shifting from 1 to 32 A g⁻¹ (1481 F g⁻¹), and only a 10% loss of its capacitance even after 4000 recycles at a consistent current density of 10 A g⁻¹. A symmetric supercapacitor based on NWM NiCo₂O₄ was assembled and it exhibited a high specific capacitance of 269 F g⁻¹ at 1 A g⁻¹ and a preferable energy density of 38.3 W h kg⁻¹ at a power density of 396 W kg⁻¹. The optimum overall performance of both high rate capability and cycle stability make the network-like mesoporous NiCo₂O₄ the prime candidate for application in electrochemical supercapacitors.