High-performance supercapacitors based on superior Co 3O 4 nanorods electrode for integrated energy harvesting-storage system

摘要

The Co3O4nanorods (NR-Co3O4) electrode is synthesized by using a calcination-process assisted hydrothermal method. Each Co3O4nanorod possesses porous structure with well-defined nanoparticles. The unique NR-Co3O4electrode exhibits the superior electrochemical performances, including a specific capacity of 1272?C?g?1at a current density of 1.89?A?g?1and 90.3% of capacity retention after 18,000 cycles at 23.58?A?g?1. The NR-Co3O4//active carbon (AC) device is also assembled to probe the virtues of NR-Co3O4electrode, manifesting a maximum energy density and power density of 55.4?Wh kg?1and 4490?W?kg?1, respectively. Amazingly, the NR-Co3O4//AC device exhibits the super-long cycling stability with 90.4% retention ratio after 36,000 cycles. Furthermore, an energy harvesting-storage system is constructed by integrating the commercial solar panel with the power package composing of four NR-Co3O4//AC devices in-series, witnessing the fast photo-charge and discharge capability of NR-Co3O4//AC device. These facts strongly demonstrate the synthesized NR-Co3O4is promising towards the practical application for self-powered technology in future.