Nickel phosphate nanowires directly grown on Ni foam as binder-free electrode for pseudocapacitors

Abstract In this work, nickel phosphate nanowires are synthesized onto Ni foam via a facile and low-cost hydrothermal method. The scanning electron microscopy images exhibit that nanowire morphology with uniform diameter distribution is evenly grown on the Ni foam surface and notably, no other morphology is observed during the nanowire growth. When the obtained NiHPO4 nanowires are used as the cathode, it exhibits high specific capacitance of 1472 F g−1 at of 1 A g−1 in supercapacitor. Further, the NiHPO4 nanowires electrode is also used as anode to assemble an asymmetric cell, in which activated carbon acts as cathode. High specific capacitance of 98.62 F g−1 is obtained at 0.5 A g−1. These results demonstrate that NiHPO4 nanowires display great potential for using as highly active electrode materials for electrochemical energy storage applications.