In this study, highly porous 2D ZnCo2O4 nanoflakes of cubic crystalline structure are synthesized for the first time via an ionothermal method using a deep eutectic solvent (DES). The synthesized ZnCo2O4 features a large surface area of 115.18 m2 g−1 with a high pore volume of 0.411 cm3 g−1. As a result, it exhibits a high specific capacity of 311.26 mAh g−1 at a current density of 1.0 A g−1, along with an excellent rate capability (60.4% retention at 15 A g−1). Electrochemical impedance spectroscopy (EIS) study indicates a low Warburg diffusion (Zw) value of only 0.93 Ω, which suggests the fast movement of OH− ions into the ZnCo2O4 electrode through its porous structure. The ZnCo2O4//AC asymmetric supercapacitor (ASC) exhibits a high energy density of 21.2 Wh kg−1 at a power density of 800 W kg−1, an ultrahigh power density of 12 kW kg−1 for an energy density of 8 Wh kg−1, and long cyclic stability, with almost 100% capacity retention after 10,000 cycles.
|Journal||Journal of Electroanalytical Chemistry|
|Publication status||Published - 2021 Jul 1|
Bibliographical noteFunding Information:
Funding: This work was supported by the National Research Foundation (NRF) grant funded by the Ministry of Science, ICT, and Future Planning ( NRF-2018M3A7B4071535 ), and Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education ( NRF-2019R1A6A1A11055660 ).
© 2021 Elsevier B.V.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Chemical Engineering(all)