Controllable synthesis of mesoporous Co 3 O 4 nanoflake array and its application for supercapacitor

Abstract A mesoporous Co 3 O 4 nanoflake array grown on carbon cloth is prepared by a facile electrodeposition method with a following annealing process. The as-prepared Co 3 O 4 nanoflake possesses a continuous mesopores ranging from 2 to 5 nm and grows tightly on the substrate forming a porous net-like structure with macropores of 20–200 nm. The electrochemical performance of the mesoporous Co 3 O 4 nanoflake arrays as pseudocapcitor electrode are investigated by cyclic voltammograms and galvanostatic charge/discharge tests in 2 M KOH. The as-prepared Co 3 O 4 array exhibits a high discharge capacitance and excellent rate capability with 450 F g −1 , 436 F g −1 , 408 F g −1 , 380 F g −1 and 363 F g −1 at 1, 2, 4, 10, and 20 A g −1 , respectively. The specific capacitance of 81% is maintained from 1 A g −1 to 20 A g −1 . The electrode also shows rather good cycling stability and exhibits a specific capacitance of 414 F g −1 after 5000 cycles.