Co-precipitation synthesis of CuCo2O4 nanoparticles for supercapacitor electrodes with large specific capacity and high rate capability

Ultra-fine CuCo2O4 nanoparticles were synthesized using a facile co-precipitation method assisted by NaBH4 and CTAB, and they were explored as supercapacitor electrode material to achieve a large spe-cific capacity and a high rate capability. The synthesized CuCo2O4 -250 nanoparticles had a large sur -face area of 159.6 m(2)g(-1), which provided numerous active sites to enhance their specific capacity. The abundant mesopores with a pore volume of 0.3599 cm(3) g(-1) effectively provided numerous channels for the electrolyte ions to diffuse onto the active surface of nanoparticles. The CuCo2O4 -250 nanoparticles based electrodes exhibited both battery-type and capacitive-type behavior in the charging/discharging processes. It achieved a large specific capacity of 401.2 C g(-1) at a current density of 0.5 A g(-1) in 2 M KOH electrolyte. Results showed that when the current density was increased from 1 A g(-1) to 10 A g(-1), a retained specific capacity of 77.5% was achieved, indicating a good rate capability. An asymmetric su-percapacitor with CuCo2O4 -250 nanoparticles and activated carbon as positive and negative electrodes exhibited a high energy density of 29.5 Wh kg(-1) at a power density of 832.6 W kg(-1) and a capacity retention of 72.7% at 10 A g(-1) after 10,0 0 0 cycles. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Ultra-fine CuCo2O4 nanoparticles were successfully synthesized using a co-precipitation method, showing great potential as supercapacitor electrode material with high specific capacity and rate capability. The nanoparticles had a large surface area and abundant mesopores, allowing for efficient ion diffusion and exhibiting both battery-type and capacitive-type behavior during charging/discharging processes. The asymmetric supercapacitor using CuCo2O4 nanoparticles achieved a high energy density at a power density and maintained good capacity retention after cycles.