Binder-free mesoporous NiCo(CO3)(OH)(2) nanowire arrays were grown using a facile hydrothermal technique. The Co-2(CO3)(OH)(2) in NiCo(CO3)(OH)(2) nanowire arrays was well-decorated as nano-dot scale (a few nanometer). In addition, increasing cobalt content in nickel compound matrix, NiCo(CO3)(OH)(2) nanowire arrays were separately uniformly grown without agglomeration on Ni foam, providing a high specific surface area to help electrolyte access and ion transfer. The enticing composition and morphology of the NiCo(CO3)(OH)(2) nanowire exhibit a superior specific capacity of 1288.2 mAh g(-1) at a current density of 3 A g(-1) and excellent cycling stability with the capacity retention of 80.7% after 10,000 cycles. Furthermore, an asymmetric supercapacitor composed of the NiCo(CO3)(OH)(2) composite as a positive electrode and the graphene as a negative electrode presented a high energy density of 35.5 W h kg(-1) at a power density of 2555.6W kg(-1) and satisfactory cycling stability with 71.3% capacity retention after 10,000 cycles. The great combination of the active nano-dot Co-2(CO3)(OH)(2) and the individually grown NiCo(CO3)(OH)(2) nanowires made it a promising electrode material for asymmetric supercapacitors. A well-developed nanoarchitecture of the nano-dot Co-2(CO3)(OH)(2) decorated NiCo(CO3)(OH)(2) composite could pave the way for an excellent electrode design for high-performance supercapacitors. (C) 2017 Elsevier B.V. All rights reserved.