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The inferior energy density limits the practical application and sustainable development of supercapacitors. Excellent electrode materials can effectively improve the specific capacitance and operating potential window. Thus, we deposit brush-like nickel ferrite (NiFe 2 O 4) nanosheets and CuCo 2 O 4 /CuO nanowire arrays to construct a binder-free electrode with tree-like CuCo 2 O 4 /CuO/NiFe 2 O 4 arrays. The resulting CuCo 2 O 4 /CuO/NiFe 2 O 4 electrode shows an outstanding specific capacitance (2067 F/g) and wide potential window (−0.1-0.6 V). The contribution rate of surface faradaic redox reaction is calculated to be 71% at 1 mV/s and assembled CuCo 2 O 4 /CuO/NiFe 2 O 4 //AC device realizes a remarkable energy density (77.1 Wh/kg at power density of 851.4 W/kg) and cyclic performance (92.9% of initial specific capacitance retained after 10,000 cycles). Apparently, the CuCo 2 O 4 /CuO/NiFe 2 O 4 electrode as a novel binder-free electrode has great application potential and our work offers a novel idea to construct the arrays of multicomponent composite materials. [ABSTRACT FROM AUTHOR]

Hybrid transitional metals oxides have been attracted more and more attention in the field of supercapacitors. However, the design of structure and composition of materials is always a challenge due to tedious preparation process and difficult structure construction. Based on above issue, we construct novel raspberry-like Ni/NiO/CoO/Mn 3 O 4 hierarchical structures (NNCMs) with excellent electrochemical performances by one-step hydrothermal process in this work. The introduction of metallic Ni and well-designed hierarchical structures can result in well improved conductivity for electrode material, sufficient channels and active sites for electrolyte ions to enter and contact with electrode material. The NNCMs-16 electrode exhibits a high specific capacitance of 1964 F g−1 and superior cycling stability (95% of initial specific capacitance after 10000 cycles). The assembled NNCMs-16//AC device delivers outstanding energy densities of 70.4 Wh kg−1 at power densities of 794.5 W kg−1. Thus, the raspberry-like NNCMs-16 hierarchical structures can be regarded as promising materials for practical supercapacitors and this work also provides a valuable reference for the preparation and application of high performance electrode materials. [ABSTRACT FROM AUTHOR]

A simple synthesize method of hybrid transition metal oxides is important for the application of electrodes materials. In this work, we report one-pot hydrothermal method to synthesize 3D hierarchical MnMoO 4 /NiWO 4 microspheres. Notably, the 3D hierarchical MnMoO 4 /NiWO 4 microspheres electrodes with a MnMoO 4 /NiWO 4 molar ratio of 4:3 present outstanding electrochemical performance. The excellent specific capacitance of the hybrid materials is 598 F g -1  at a discharge current density of 1 A g −1 and the capacitance retains 82% of its initial capacitance even after 5000 cycles, which are attributed to the obtained 3D hierarchical MnMoO 4 /NiWO 4 microspheres are constituted by self-assembly MnMoO 4 nanoflakes and NiWO 4 nanoparticals and feature with abundant transportation shortcuts for electrolyte ions and excellent electrochemical performance. The results reveal that the 3D hierarchical MnMoO 4 /NiWO 4 microspheres have great application prospect for electrochemical energy storage and the quick and facile method provides a new avenue for the preparation of hybrid materials. [ABSTRACT FROM AUTHOR]

Hierarchical CoFeO/NiFeO nanocomposites are prepared via a facile hydrothermal method, in which CoFeO nanoparticles are coated by NiFeO nanoparticles to form a novel nanostructure. Comparing with the single component of either CoFeO electrodes or NiFeO electrodes, the as-prepared hierarchical CoFeO/NiFeO nanocomposites electrodes deliver a higher specific capacitance of 269 F g at a current density of 1 A g and exhibit capacity retention of 81% after 10000 charge-discharge cycles. The improved electrochemical performance demonstrates that hierarchical CoFeO/NiFeO nanocomposites are promising materials and provide a new idea for future generation supercapacitors. [ABSTRACT FROM AUTHOR]