Three dimensional hexagon-like phosphrous (P) doped Ni(OH)(2) rod arrays grown on Ni foam (NF) are fabricated by a facile and green one-step hydrothermal process. Ni foam is only reacted in a certain concentration of P containing H2O2 aqueous solution. The possible growth mechanism of the P doped Ni(OH)(2) rod arrays is discussed. As a battery-type electrode material in situ formed on Ni foam, the binderfree P doped Ni(OH)(2) rod arrays electrode displays a ultrahigh specific areal capacitance of 2.11C cm(-2) (3.51 F cm(-2)) at 2 mA cm(-2), and excellent cycling stability (95.5% capacitance retention after 7500 cycles). The assembled all-solid-state asymmetric supercapacitor (AAS) based on such P doped Ni(OH)(2) rod arrays as the positive electrode and activated carbon as the negative electrode achieves an energy density of 81.3 Wh kg(-1) at the power density of 635 W kg(-1). The AAS device also exhibits excellent practical performance, which can easily drive an electric fan (3 W rated power) when two AAS devices are assembled in series. Thus, our synthesized P doped Ni(OH)(2) rod arrays has a lot of potential applications in future energy storage prospects. (C) 2017 Elsevier B.V. All rights reserved.