Embedding Co2P nanoparticles in Cu doping carbon fibers for Zn-air batteries and supercapacitors.

ABSTRACT

Developing highly efficient and non-precious materials for Zn-air batteries (ZABs) and supercapacitors (SCs) are still crucial and challenging. Herein, electronic reconfiguration and introducing conductive carbon-based materials are simultaneously conducted to enhance the ZABs and SCs performance of Co2P. We develop a simple and efficient electrospinning technology followed by carbonization process to synthesize embedding Co2P nanoparticles in Cu doping carbon nanofibers (Cu-Co2P/CNFs). As a result, the 7% Cu-Co2P/CNFs presents high oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity (half-wave potential of 0.792 V for ORR, an overpotential of 360 mV for OER). The ZABs exhibit a power density of 230 mW cm-2and excellent discharge-charge stability of 80 h. In addition, the 7% Cu-Co2P/CNFs show the specific capacitance of 558 F g-1at 1 A g-1. Moreover, the 7% Cu-Co2P/CNFs//CNFs asymmetric supercapacitor was assembled applying 7% Cu-Co2P/CNFs electrode and pure CNFs, which exhibits a high energy density (25.9 Wh kg-1), exceptional power density (217.5 kW kg-1) and excellent cycle stability (96.6% retention after 10 000 cycles). This work may provide an effective way to prepared Co2P based materials for ZABs and SCs applications.