Metal carbonate hydroxide is a promising electrode material for advanced supercapacitors but suffers from the poor electronic conductivity. Herein, we address this issue through the in-situ formation of Ni1/3Co2/3(CO3)(0.5)OH center dot 0.11H2O anchoring onto the surface of polypyrrole nanotubes via a hydrothermal method. The Ni1/3Co2/3(CO3)(0.5)OH center dot 0.11H(2)O/polypyrrole nanotubes composites possess high specific surface area and electronic conductivity, resulting in large charge storage and fast charge/discharge rate. The synthesized composite electrodes exhibit a high specific capacitance of 964.8 F g(-1) at 1 A g(-1) and low the equivalent series resistance of 0.24 Omega Moreover, the assembled asymmetric supercapacitors exhibit high energy density of 41.86 Wh kg(-1) with a power density of 562 W kg(-1), and high power density of 11.25 kW kg(-1) with an energy density of 16.97 Wh kg(-1). The capacitance retention remains 80.2% after 5000 cycles at 5 A g(-1), indicating the excellent cycling stability. The results indicate that Ni1/3Co2/3(CO3)(0.5)OH center dot 0.11H(2)O/polypyrrole nanotubes composites are a potential electrode material for high-performance supercapacitors. (C) 2018 Elsevier Ltd. All rights reserved.