Design and fabrication of hierarchical heterostructure CuCo2O4@PPy based asymmetric device with ultra high capacitance and attractive cycling performance

Abstract A facile, controllable and low cost hydrothermal method has been used to fabricate CuCo2O4 nanorods (CCN) CuCo2O4 nanorods@PPy nanowires (CCNP) arrays on Ni foam. The impressive heterostructures are favorable to shortening the paths ion/electron diffusion, giving a superior specific surface area and revealing richer electroactive sites. The electrochemical properties are tested in three-and two-electrode configurations, signifying a better specific capacitance and a long-term cycling stability. Remarkably, the CCNP heterostructure electrode exhibits an excellent value of 2272 Fg−1 at 2 Ag−1. The specific capacitance retention is almost 91 and 96 % for CCN and CCNP electrodes at 20 Ag−1 after 5000 cycle. Extremely, the optimized CuCo2O4@PPy//AC ASC cell is cycled reversibly in a wide voltage region as high as 1.4 V and exhibits a specific capacitance of 91 Fg-1 even at a high current density of 20 Ag-1 with a maximum energy density of 52 Wh kg-1.