High conductivity Ni12P5 nanowires as high-rate electrode material for battery-supercapacitor hybrid devices

Abstract

Abstract Battery-supercapacitor hybrid (BSH) devices are emerging wide application in new energy storage, electric vehicles and other fields with excellent performance in energy storage and power amplifier. However, the development of suitable cathode materials is far from being satisfactory and limits the performance. Here, we demonstrate that the Ni12P5 nanowires with high conductivity can be used as suitable cathode materials for BSH devices. The Ni12P5 nanowires are synthesized adopting simple one-step hydrothermal method based on the anion overflowed formation mechanism, which deliver a high reversible capacity of 707.2 C g−1 at 1 A g−1 (481.7 C g−1 at 10 A g−1, the retention rate is over 68%) and good cyclic stability. The Ni12P5//activated carbon hybrid device shows energy density of 108.2 Wh kg−1 at the power density of 0.896 kW kg−1 and 48.78 Wh kg−1 at 8.96 kW kg−1. It is found that the high conductivity of the Ni12P5, which mainly stems from its 0 band-gap metal properties, gives rise to high rate performance of BSH devices. The observed high reversible capacity, excellent rate capability and cyclability of nickel phosphide nanowires make it competitive if not superior when compared to other cathode materials.