MOF-Derived Hollow and Porous Co₃O₄ Nanocages for Superior Hybrid Supercapacitor Electrodes

Abstract

The development of hollow and porous materials is essential for effective energy storage and conversion owing to their facile transport of electrons and ions. Herein, through a facile low-temperature thermal decomposition reaction of ZIF-67 crystals, hollow Co 3 O 4 nanocages composed of numerous nanoparticles with a porous structure are prepared. These hollow and porous Co 3 O 4 nanocages (Co 3 O 4 HPCs) possess a pore size distribution between 20 and 60 nm and a large Brunauer−Emmett−Teller surface area of 211.79 m 2 g −1 . Benefitting from the large surface area, a maximum specific capacitance of 140.0 F g −1 can be calculated. Furthermore, the assembled Co 3 O 4 HPCs//activated carbon hybrid supercapacitor can deliver an energy density of 19.8 W h kg −1 and 97.3% capacitance retention during 5000 cycles. As a result of good electrochemical performance of these Co 3 O 4 HPCs, they can be a promising electrode for supercapacitors.

One-Step Solvothermal Synthesis of Raspberry-like NiCo-MOF for High-Performance Flexible Supercapacitors for a Wide Operation Temperature Range

“…While the power density reaches its maximum of 12,047 W/kg, the energy density remains 45.53 Wh/kg. As shown in Figure i and Tables and , compared to the previous research studies on related MOFs, − the energy density of our prepared device is significantly improved. It indicates that the electrode material prepared using our experimental method will have more advantages than those in the literature.…”

Co3O4@NiMoO4 composite electrode materials for flexible hybrid capacitors

“…Figure 6e is a Ragone plot of several devices. NiMoO 4 //AC device can deliver an energy density of 36.1 Wh/kg at 2700 W/kg, which is higher than those reported in previous literatures [27][28][29][30][31][32][33][34].…”

Nanostructured mixed transition metal oxide spinels for supercapacitor applications

“…Nanocage morphology is another example to fully utilize the pores in Co 3 O 4 . 58 Further emphases have been given on synthesis methods, rationally designing the material structure, and evolution of morphology in other Co 3 O 4 EES studies including the annealing of electrode materials. 59,60 3.1.2.…”