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A three-dimensional network of carbon nanotubes (3DNC) coaxially coated with manganese oxides (MnO x ) is used as an electrode for supercapacitors. 3DNC serves as a stable and conductive framework for controlled electrochemical deposition (ECD), and provides sufficient voids for fast ionic transport and diffusion. The coated thin layer MnO x reduces ion diffusion and electron transport distance, enabling fast reversible faradic reactions.As one of the most promising electrochemical energy storage materials, manganese oxides have been studied extensively as supercapacitor electrode materials due to their low cost, nontoxicity and theoretically high capacity of about 1370 F g À1 . 1-10In particular, low dimensional nanostructured MnO x with different morphologies has been developed as an electrode material and showed its advantages in charge storage capability. 4,9,11-15 However, its intrinsic poor electrical conductivity is a current drawback to utilize MnO x as a high-rate performance supercapacitor.1, [3][4][5]7 To overcome this problem, an effective way is to incorporate MnO x with other metal elements (Ni, Ru, Al, Sn and Pb etc.) 6,7 or porous, high surface area and conductive nanostructures such as carbonaceous sphere, 16 carbon nanotubes, 17 graphene 18 and conductive polymers. 19Among those for advanced metal oxide-based hybrid nanostructure design, coaxial thin layer structure with ordered nanostructure arrays is considered as one of promising approaches for achieving the goal. Previous research has shown only a very thin layer of metal oxide material (several tens of nanometers from the surface) participated in the redox reaction. 20 Hence, coaxial thin layer structure could allow cations to intercalate into entire active materials and shorten electron transport distance inside the active materials. Yamauchi Y. et al.17 reported on the development of multiwalled carbon nanotube-manganese oxide core-shell structures utilized for asymmetric supercapacitor applications which shows a specic capacitance (C sp ) of 185 F g À1 at a scan rate of 5 mV s À1 . Ordered nanostructure array is also an excellent candidate in aspect of providing a conductive path way not only for electron transport but also for resolving the ionic diffusion and transportation issues of supercapacitor electrodes. Zhu S. J. et al. 21 reported the development of coaxial mesoporous manganese dioxide/amorphous carbon nanotubes arrays for advanced asymmetric supercapacitors which exhibit the optimized pseudocapacitance performance (362 F g À1 ) with good cycling stability, and ideal rate capability. Ionic diffusion and transportation are critical points to improve superior energy density, power density and charge efficiency due to shorter diffusion length in void volume. 22,23 Longer life cycle and stronger volume retention during the charge and discharge process can be obtained through the nanostructures. Here, we demonstrate a coaxial thin layer MnO x hybrid nanostructure array for high performance MnO x supercapacitors.In our previous res...